Dogfood run unable to download artifact

**Describe the bug**

CI is hitting this issue https://github.com/actions/download-artifact/issues/486.

> Unable to download artifact(s): Failed to GetSignedArtifactURL: Received non-retryable error: Failed request
> -- https://github.com/haskell/cabal/actions/runs/30026457823

One suggested fix is to match the versions of `upload-artifact` and `download-artifact`. The latest upload is `v7` so this change would be ...

```diff
$ git diff
diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
index 6b06b0a32..84e15d10f 100644
--- a/.github/workflows/validate.yml
+++ b/.github/workflows/validate.yml
@@ -421,7 +421,7 @@ jobs:
cabal-version: latest # default, we are not using it in this job

- name: Download cabal executable from workflow artifacts
- uses: actions/download-artifact@v8
+ uses: actions/download-artifact@v7
with:
name: cabal-${{ runner.os }}-${{ env.CABAL_ARCH }}
path: cabal-head
@@ -445,7 +445,7 @@ jobs:
needs: [validate, validate-old-ghcs, build-alpine, dogfooding]

steps:
- - uses: actions/download-artifact@v8
+ - uses: actions/download-artifact@v7
with:
pattern: cabal-*
path: binaries
@@ -473,7 +473,7 @@ jobs:
needs: [validate, validate-old-ghcs, build-alpine, dogfooding]

steps:
- - uses: actions/download-artifact@v8
+ - uses: actions/download-artifact@v7
with:
pattern: cabal-*
path: binaries
```

Another suggested fix would be to match the `run-id` explicitly.

Start with .github/workflows/validate.yml and inspect the download-artifact steps in the dogfooding and downstream jobs, along with the corresponding upload-artifact version. Check the linked download-artifact issue for the failure context, then verify the selected version or run-id adjustment by rerunning the affected CI workflow and confirming the artifacts download successfully.

Written by the indexing model from the issue text.