Build: Add CI check to enforce runtime-deps.gradle coverage across all modules

[kevinjqliu]

This adds a verifyRuntimeDepsApplied task that fails CI if a subproject is missing
runtime-deps.gradle and is not in an explicit exclusion list. This prevents new
shadow JAR modules from being added without dependency tracking.

Changes

• Added verifyRuntimeDepsApplied task to build.gradle with an exclusion list of
  modules that don't ship fat JARs
• Wired it as a dependency of checkAllRuntimeDeps so it runs in CI automatically
• Updated workflow comment in runtime-deps.gradle

How it works

Every subproject must either:

1. Apply runtime-deps.gradle (produces a checkRuntimeDeps task), or
2. Be listed in the exclusion set

If a new module is added without doing either, CI fails with a message naming
the uncovered module and instructions to fix it.

Testing

• ./gradlew checkAllRuntimeDeps -q -DallModules=true passes
• Verified the task catches missing modules by temporarily removing
  runtime-deps.gradle from aws-bundle

[kevinjqliu]

@RussellSpitzer wdyt? this should prevent future additions potentially missing the the runtime-deps.txt file

[RussellSpitzer]

The original discussion I had with Ryan (he did your approach) is I just thought it would be easier to maintain the 'needs check list' then the 'ignore list' . I don't have strong feelings

[kevinjqliu]

@rdblue thoughts?