chore: pin GHA PM action version (#1199)

Author: nipsufn

.github/workflows/pm.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: ory-corp/planning-automation-action@main
+      - uses: ory-corp/planning-automation-action@v0.1
         with:
           organization: ory-corp
           project: 5