Skip collection API checks in test (all) job

The test (all) job runs when non-collection/non-topic files change (e.g.,
Gemfile, Rakefile updates). Running the full collection rename/existence
API checks (~300 GraphQL calls) is redundant for these changes because:

1. The collections-renames workflow runs hourly to detect and fix renames
2. The test (collections) job already validates collections when
   collection files are modified

This change adds a SKIP_COLLECTION_API_CHECKS env var that causes the
expensive API-based rename test to be skipped in the all job, reducing
its runtime from ~16 minutes to ~2 minutes.

Author: kenyonj

.github/workflows/test.yml

@@ -58,3 +58,4 @@ jobs:
           TOPIC_FILES: ${{ steps.topics.outputs.changed }}
           COLLECTION_FILES: ${{ steps.collections.outputs.changed }}
           TEST_ALL_FILES: ${{ steps.all.outputs.changed }}
+          SKIP_COLLECTION_API_CHECKS: ${{ matrix.test_type == 'all' && '1' || '' }}

test/collections_test.rb

@@ -137,6 +137,10 @@
       end
 
       it "fails if a user, organization, or repository has been renamed or removed" do
+        if ENV["SKIP_COLLECTION_API_CHECKS"]
+          skip "Skipping collection API checks (rename detection handled by collections-renames workflow)"
+        end
+
         errors = []
         repos_to_check = []
         users_to_check = []