chore: remove PR branching strategy workflow file

.github/workflows/pr-target-branch-check.yml

-name: Check PR Branching Strategy
-on:
-  pull_request:
-    types: [opened, synchronize, reopened, edited]
-
-jobs:
-  check-branching-strategy:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Enforce branching strategy
-        run: |
-          if [[ "${{ github.base_ref }}" == "main" ]]; then
-            if [[ "${{ github.head_ref }}" != "alpha" ]]; then
-              echo "Error: Pull requests to 'main' are only allowed from the 'alpha' branch."
-              exit 1
-            fi
-          elif [[ "${{ github.base_ref }}" != "alpha" ]]; then
-            echo "Error: Pull requests must be targeted to the 'alpha' or 'main' branch."
-            exit 1
-          fi
-          echo "Branching strategy check passed."
\ No newline at end of file