get branch name for base

.github/workflows/update-snippets.yaml

@@ -1,8 +1,6 @@
 name: Generate Snippets
 'on':
   push:
-    tags:
-      - '*'
   workflow_dispatch: null
 jobs:
   generate-snippets:
@@ -12,6 +10,10 @@ jobs:
         - name: Generate Snippets
           run: |
             ./scripts/make_mdx.sh snippets/destination_connectors snippets/source_connectors
+        - name: Extract Branch Name
+          id: extract-branch
+          shell: bash
+          run: echo "branch=$(echo ${GITHUB_REF#refs/heads/})" >> $GITHUB_ENV
         - name: Create Pull Request
           uses: peter-evans/create-pull-request@v5
           with:
@@ -26,4 +28,4 @@ jobs:
             delete-branch: true
             body: |
               This automated pull request includes updated code snippets.
-            base: ${{ github.ref }}
+            base: ${{ steps.extract-branch.outputs.branch }}