ops: remove --self-test from attribution-trailer lint

Operator ruling on PR #4433: the self-test doubled the script size
without adding value. Drops the --self-test mode + fixtures from
check-attribution-trailers.sh and the CI self-test step that invoked
it. The anchored trailer regex and the real BASE..HEAD scan are
unchanged.

Refs #4432

.forgejo/workflows/ci.yml

@@ -53,8 +53,6 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - name: self-test
-        run: sh scripts/check-attribution-trailers.sh --self-test
       - name: lint
         run: sh scripts/check-attribution-trailers.sh
 

scripts/check-attribution-trailers.sh

@@ -12,41 +12,10 @@
 #
 # Scope is the PR's commits (BASE..HEAD), not entire history — old commits
 # must not fail the build.
-#
-# Run with --self-test to check the pattern against fixtures instead of
-# scanning git history.
 set -eu
 
 trailer_re='^[[:space:]]*co-authored-by:.*(claude|anthropic|noreply@anthropic\.com)'
 
-if [ "${1:-}" = "--self-test" ]; then
-  fail=0
-
-  assert_match() {
-    if ! printf '%s\n' "$2" | grep -qiE "$trailer_re"; then
-      echo "self-test FAILED (expected match): $1" >&2
-      fail=1
-    fi
-  }
-  assert_no_match() {
-    if printf '%s\n' "$2" | grep -qiE "$trailer_re"; then
-      echo "self-test FAILED (expected no match): $1" >&2
-      fail=1
-    fi
-  }
-
-  assert_match "bare trailer" 'Co-Authored-By: Claude'
-  assert_match "full trailer with email" 'Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>'
-  assert_match "lowercase trailer" 'co-authored-by: claude'
-  assert_no_match "ordinary message" 'fix: correct off-by-one in parser'
-  assert_no_match "prose mention of the trailer" 'ops: add CI lint for Co-Authored-By/Claude/Anthropic trailers'
-
-  if [ "$fail" -eq 0 ]; then
-    echo "self-test OK"
-  fi
-  exit "$fail"
-fi
-
 if [ -n "${GITHUB_BASE_REF:-}" ]; then
   base="origin/${GITHUB_BASE_REF}"
 else