ci: remove workflow files from path filters

The CI and regression path filters included their own workflow files,
which meant any PR that changed CI config would trigger the full
build/test/regression suite. Workflow file changes don't need code
validation — they need a test run of the workflow itself, which
happens automatically.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -30,8 +30,6 @@ jobs:
               - "pnpm-workspace.yaml"
               - "tsconfig*.json"
               - "Dockerfile*"
-              - ".github/workflows/ci.yml"
-              - ".github/workflows/regression.yml"
 
   build:
     name: Build

.github/workflows/regression.yml

@@ -24,7 +24,6 @@ jobs:
               - "scripts/**"
               - "Dockerfile*"
               - "pnpm-lock.yaml"
-              - ".github/workflows/regression.yml"
 
   regression-shards:
     needs: changes