Investigate how to get actionlint to do better

https://github.com/knative/actions/pull/109 disables actionlint on composite actions (there is an open feature request for this https://github.com/rhysd/actionlint/issues/46) also it disables shellcheck from actionlint which we don't want, but it is throwing shellcheck errors which should not be there:

◗ ~/go/bin/actionlint  reusable-releasability.yaml 
reusable-releasability.yaml:40:9: shellcheck reported issue in this script: SC2129:style:1:1: Consider using { cmd1; cmd2; } >> file instead of individual redirects [shellcheck]
   |
40 |         run: |
   |         ^~~~
reusable-releasability.yaml:62:14: workflow command "set-output" was deprecated. use `echo "{name}={value}" >> $GITHUB_OUTPUT` instead: https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions [deprecated-commands]
   |
62 |         run: |
   |              ^
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1009:info:4:1: The mentioned syntax error was in this simple command [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1078:warning:4:126: Did you forget to close this double quoted string? [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1079:info:5:15: This is actually an end quote, but due to next char it looks suspect [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1078:warning:10:22: Did you forget to close this double quoted string? [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1079:info:11:26: This is actually an end quote, but due to next char it looks suspect [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1073:error:13:39: Couldn't parse this double quoted string. Fix to allow more checks [shellcheck]
   |
74 |         run: |
   |         ^~~~
reusable-releasability.yaml:74:9: shellcheck reported issue in this script: SC1072:error:16:1: Expected end of double quoted string. Fix any mentioned problems and try again [shellcheck]
   |
74 |         run: |
   |         ^~~~

Strangely running using the same workflow on the actionlint playground does not have the shellcheck issue (It appears shellcheck is not ran in the playground)... permalink

Start by running actionlint against reusable-releasability.yaml and compare the local output with the actionlint playground result. Read pull request 109 and actionlint issue 46 to understand the composite-action and shellcheck context. Done means identifying why the reported shellcheck diagnostics differ and documenting or reproducing the appropriate fix.