chore(e2e): Fix slack message (#3079)

Author: moduli

.github/workflows/test-e2e-admin-ui.yaml

@@ -204,4 +204,4 @@ jobs:
           token: ${{ secrets.SLACK_BOT_TOKEN }}
           payload: |
             channel: ${{ secrets.SLACK_CHANNEL_ID }}
-            text: ":x: admin ui e2e tests failed: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Branch:* ${{ github.repository }}:${{ github.event.ref }}"
+            text: ":x: admin ui e2e tests failed: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Branch:* ${{ github.repository }}:${{ github.head_ref }}"

.github/workflows/test-e2e-desktop.yaml

@@ -125,4 +125,4 @@ jobs:
           token: ${{ secrets.SLACK_BOT_TOKEN }}
           payload: |
             channel: ${{ secrets.SLACK_CHANNEL_ID }}
-            text: ":x: desktop client e2e tests failed: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Branch:* ${{ github.repository }}:${{ github.event.ref }}"
+            text: ":x: desktop client e2e tests failed: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Branch:* ${{ github.repository }}:${{ github.head_ref }}"