fix(ci): pin kubernetes-e2e setup-go SHA and refresh --help snapshots

The post-merge CI surfaced two failures introduced by the origin/main merge
and the experimental-flag change:

- verify (SHA-pin): the kubernetes-e2e job's "Set up Go" step still pinned the
  pre-merge actions/setup-go@4a36011 (# v6) while the merge bumped every other
  occurrence to @924ae3a; align it so SHA-pin verification passes.
- Acceptance Tests (linux/macos/windows): marking `atmos kubernetes`
  experimental changed `atmos --help` to print `kubernetes [command]
  [EXPERIMENTAL]`, so the three top-level help golden snapshots were stale.
  Regenerated via -regenerate-snapshots (only the kubernetes line changed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: osterman

.github/workflows/test.yml

@@ -562,7 +562,7 @@ jobs:
 
       - name: Set up Go
         # setup-go v6 requires runner v2.327.1+ and can affect toolchain handling.
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
+        uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6
         with:
           go-version-file: "go.mod"