release-26.3: testutils/lint: TestNightlyLint failed

testutils/lint.TestNightlyLint [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_LintURLsBazel/21455783?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_LintURLsBazel/21455783?buildTab=artifacts#/) on release-26.3 @ [decaea45a5634c34ec3ec504ca48181da0c9f721](https://github.com/cockroachdb/cockroach/commits/decaea45a5634c34ec3ec504ca48181da0c9f721):

```
I260807 05:25:06.492424 90 (gostd) urlcheck.go:245 [-] 11 Checking https://www.cockroachlabs.com/docs/v26.3/rollback-transaction.html...
I260807 05:25:06.492511 33 (gostd) urlcheck.go:245 [-] 12 Checking https://www.cockroachlabs.com/docs/v26.3/grant.html...
I260807 05:25:06.492600 92 (gostd) urlcheck.go:245 [-] 13 Checking https://www.cockroachlabs.com/docs/v26.3/show-default-privileges...
I260807 05:25:06.492638 89 (gostd) urlcheck.go:245 [-] 14 Checking https://www.cockroachlabs.com/docs/v26.3/set-vars.html...
I260807 05:25:06.492723 83 (gostd) urlcheck.go:245 [-] 15 Checking https://www.cockroachlabs.com/docs/v26.3/show-backup.html...
I260807 05:25:06.492794 91 (gostd) urlcheck.go:245 [-] 16 Checking https://www.cockroachlabs.com/docs/v26.3/revoke.html...
I260807 05:25:06.492831 86 (gostd) urlcheck.go:245 [-] 17 Checking https://www.cockroachlabs.com/docs/v26.3/show-tables.html...
I260807 05:25:06.492890 85 (gostd) urlcheck.go:245 [-] 18 Checking https://www.cockroachlabs.com/docs/v26.3/alter-trigger.html...
I260807 05:25:06.493004 32 (gostd) urlcheck.go:245 [-] 19 Checking https://www.cockroachlabs.com/docs/v26.3/show-ranges.html...
I260807 05:25:06.493083 87 (gostd) urlcheck.go:245 [-] 20 Checking https://www.cockroachlabs.com/docs/v26.3/alter-database.html...
I260807 05:25:06.552413 55 (gostd) urlcheck.go:245 [-] 21 Checking https://www.cockroachlabs.com/docs/v26.3/create-table.html...
I260807 05:25:06.803867 220 (gostd) urlcheck.go:245 [-] 22 Checking https://www.cockroachlabs.com/docs/v26.3/create-table-as.html...
I260807 05:25:06.809824 221 (gostd) urlcheck.go:245 [-] 23 Checking https://www.cockroachlabs.com/docs/v26.3/create-view.html...
I260807 05:25:06.883448 222 (gostd) urlcheck.go:245 [-] 24 Checking https://www.cockroachlabs.com/docs/v26.3/drop-database.html...
I260807 05:25:06.884394 292 (gostd) urlcheck.go:245 [-] 25 Checking https://www.cockroachlabs.com/docs/v26.3/truncate.html...
I260807 05:25:06.886282 293 (gostd) urlcheck.go:245 [-] 26 Checking https://www.cockroachlabs.com/docs/v26.3/create-function.html...
I260807 05:25:06.920358 223 (gostd) urlcheck.go:245 [-] 27 Checking https://www.cockroachlabs.com/docs/v26.3/create-index.html...
I260807 05:25:06.920751 294 (gostd) urlcheck.go:245 [-] 28 Checking https://www.cockroachlabs.com/docs/v26.3/drop-table.html...
I260807 05:25:06.921699 224 (gostd) urlcheck.go:245 [-] 29 Checking https://www.cockroachlabs.com/docs/v26.3/drop-index.html...
I260807 05:25:06.931404 309 (gostd) urlcheck.go:245 [-] 30 Checking https://www.cockroachlabs.com/docs/v26.3/restore.html...
I260807 05:25:06.961472 295 (gostd) urlcheck.go:245 [-] 31 Checking https://www.cockroachlabs.com/docs/v26.3/show-constraints.html...
I260807 05:25:06.961915 225 (gostd) urlcheck.go:245 [-] 32 Checking https://www.cockroachlabs.com/docs/v26.3/cluster-settings.html...
I260807 05:25:06.962143 322 (gostd) urlcheck.go:245 [-] 33 Checking https://www.cockroachlabs.com/docs/v26.3/alter-table.html...
I260807 05:25:06.964813 296 (gostd) urlcheck.go:245 [-] 34 Checking https://www.cockroachlabs.com/docs/v26.3/show-vars.html...
I260807 05:25:06.990636 297 (gostd) urlcheck.go:245 [-] 35 Checking https://www.cockroachlabs.com/docs/v26.3/import-into.html...
I260807 05:25:06.992089 298 (gostd) urlcheck.go:245 [-] 36 Checking https://www.cockroachlabs.com/docs/v26.3/explain.html...
I260807 05:25:06.994062 299 (gostd) urlcheck.go:245 [-] 37 Checking https://www.cockroachlabs.com/docs/v26.3/alter-function.html...
I260807 05:25:07.023347 277 (gostd) urlcheck.go:245 [-] 38 Checking https://www.cockroachlabs.com/docs/v26.3/update.html...
I260807 05:25:07.023997 300 (gostd) urlcheck.go:245 [-] 39 Checking https://www.cockroachlabs.com/docs/v26.3/alter-type.html...
I260807 05:25:07.075351 323 (gostd) urlcheck.go:245 [-] 40 Checking https://www.cockroachlabs.com/docs/v26.3/upsert.html...
I260807 05:25:07.103253 278 (gostd) urlcheck.go:245 [-] 41 Checking https://www.cockroachlabs.com/docs/v26.3/show-grants.html...
I260807 05:25:07.104044 324 (gostd) urlcheck.go:245 [-] 42 Checking https://www.cockroachlabs.com/docs/v26.3/drop-procedure.html...
I260807 05:25:07.186713 279 (gostd) urlcheck.go:245 [-] 43 Checking https://www.cockroachlabs.com/docs/v26.3/create-procedure.html...
I260807 05:25:07.219649 325 (gostd) urlcheck.go:245 [-] 44 Checking https://www.cockroachlabs.com/docs/v26.3/show-databases.html...
I260807 05:25:07.232787 301 (gostd) urlcheck.go:245 [-] 45 Checking https://www.cockroachlabs.com/docs/v26.3/alter-view.html...
I260807 05:25:07.261520 280 (gostd) urlcheck.go:245 [-] 46 Checking https://www.cockroachlabs.com/docs/v26.3/alter-procedure.html...
I260807 05:25:07.262192 302 (gostd) urlcheck.go:245 [-] 47 Checking https://www.cockroachlabs.com/docs/v26.3/show-zone-configurations.html...
I260807 05:25:07.262309 326 (gostd) urlcheck.go:245 [-] 48 Checking https://www.cockroachlabs.com/docs/v26.3/savepoint.html...
I260807 05:25:07.263387 310 (gostd) urlcheck.go:245 [-] 49 Checking https://www.cockroachlabs.com/docs/v26.3/commit-transaction.html...
I260807 05:25:07.335124 311 (gostd) urlcheck.go:245 [-] 50 Checking https://www.cockroachlabs.com/docs/v26.3/begin-transaction.html...
I260807 05:25:07.335729 312 (gostd) urlcheck.go:245 [-] 51 Checking https://www.cockroachlabs.com/docs/v26.3/alter-index.html...
I260807 05:25:07.336692 281 (gostd) urlcheck.go:245 [-] 52 Checking https://www.cockroachlabs.com/docs/v26.3/show-partitions.html...
I260807 05:25:07.347827 282 (gostd) urlcheck.go:245 [-] 53 Checking https://www.cockroachlabs.com/docs/v26.3/show-users.html...
I260807 05:25:07.348947 313 (gostd) urlcheck.go:245 [-] 54 Checking https://www.cockroachlabs.com/docs/v26.3/insert.html...
I260807 05:25:07.349376 327 (gostd) urlcheck.go:245 [-] 55 Checking https://www.cockroachlabs.com/docs/v26.3/backup.html...
I260807 05:25:07.366099 328 (gostd) urlcheck.go:245 [-] 56 Checking https://www.cockroachlabs.com/docs/v26.3/create-database.html...
nightly_lint_test.go:44: https://www.cockroachlabs.com/docs/v26.3/alter-trigger.html : 404 Not Found
1905: https://www.cockroachlabs.com/docs/v26.3/alter-trigger.html
1 errors
--- FAIL: TestNightlyLint/TestHelpURLs (1.24s)
```
Help

See also: [How To Investigate a Go Test Failure \(internal\)](https://cockroachlabs.atlassian.net/l/c/HgfXfJgM)

Same failure on other branches

- #173153 release-26.3.1-rc: testutils/lint: TestNightlyLint failed [C-test-failure O-robot T-testeng branch-release-26.3.1-rc release-blocker]
- #172711 release-26.3.0-rc: testutils/lint: TestNightlyLint failed [C-test-failure O-robot T-release branch-release-26.3.0-rc release-blocker]

/cc @cockroachlabs/test-eng

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*TestNightlyLint.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-66512

Start with testutils/lint/nightly_lint_test.go, especially the TestHelpURLs failure, and inspect the URL-checking path reported in urlcheck.go:245. Trace the source of the v26.3 alter-trigger help URL and verify the corresponding documentation route. Done means the URL resolves and TestNightlyLint/TestHelpURLs passes.

Written by the indexing model from the issue text.