ci(plugin): drop with: from the plugin job's checkout

Run 3027: the Plugin hooks job failed at checkout, before the script ran.
Adding a `with: fetch-depth: 0` block made actions/checkout@v6 fail to
extract on the act_runner —

  Cannot find module '/var/run/act/actions/<sha>/dist/index.js'

— while every bare `uses: actions/checkout@v6` in the same run succeeded.
The runner's action-cache handling is the difference, not git.

No depth was needed in the first place. The version check compares two
TREES, and a tree diff needs both trees, not a common ancestor. Verified
against a real depth-1 clone: after `git fetch --depth=1 origin
main:refs/remotes/origin/main`, both `git diff origin/main -- plugin` and
`git show origin/main:plugin/.claude-plugin/plugin.json` work. So the
explicit fetch already in the step is sufficient, and cheaper than the
full history the `with:` block was asking for.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaYUaouG9jjhATyuxCKrQs

.forgejo/workflows/ci.yml

@@ -121,21 +121,22 @@ jobs:
     container:
       image: git.fabledsword.com/bvandeusen/ci-python:3.14
     steps:
+      # Bare `uses:`, no `with:` block. Adding one made this action fail to
+      # extract on the act_runner ("Cannot find module .../dist/index.js") while
+      # every bare checkout in the same run succeeded — see run 3027. Nothing
+      # here needs `fetch-depth: 0` anyway: the version check diffs two trees,
+      # and a tree diff needs both trees, not a common ancestor. A depth-1 fetch
+      # of main's tip is enough, and cheaper.
       - uses: actions/checkout@v6
-        with:
-          # The version-bump check diffs shipped plugin content against
-          # origin/main, so it needs history — a shallow clone can't resolve it
-          # and the check would fail loudly rather than pass blind.
-          fetch-depth: 0
 
-      # On main the comparison is against itself, so only the syntax and
-      # pattern checks are meaningful there.
+      # On main the comparison would be against itself, so only the syntax and
+      # pattern checks mean anything there.
       - name: Check plugin hooks and manifest
         run: |
           if [ "${{ github.ref }}" = "refs/heads/main" ]; then
             python3 scripts/check_plugin.py --no-version
           else
-            git fetch --no-tags origin main:refs/remotes/origin/main
+            git fetch --no-tags --depth=1 origin main:refs/remotes/origin/main
             python3 scripts/check_plugin.py
           fi