Add language injection for larger bash scripts in composite actions (#16040)

.github/actions/changed-files/action.yml

@@ -18,6 +18,7 @@ runs:
     - id: changes
       name: Find changes
       shell: bash
+      # language=bash
       run: |
         BASE_REF=${{ github.base_ref }}
         

.github/actions/upload-flaky-tests/action.yml

@@ -8,6 +8,7 @@ runs:
       name: Find flaky tests
       if: github.repository == 'keycloak/keycloak'
       shell: bash
+      # language=bash
       run: |
         REPO="${{ github.repository }}"
         ISSUES_LINK="https://github.com/${{ github.repository }}/issues/"