Specify shell in workflows

Author: thomasleplus

.github/workflows/automerge.yml

@@ -16,8 +16,10 @@ jobs:
         env:
           RELEASE_TOKEN: ${{ secrets.RELEASE_TOKEN }}
         if: env.RELEASE_TOKEN != ''
+        shell: bash
         run: echo "${RELEASE_TOKEN}" | gh auth login --with-token
       - name: Enable auto-merge for Dependabot PRs
+        shell: bash
         run: |
           # Checking the PR title is a poor substitute for the actual PR changes
           # but as long as this is used only with dependabot PRs,

.github/workflows/yamllint.yml

@@ -18,6 +18,8 @@ jobs:
       - name: Check out
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install YAMLLint
+        shell: bash
         run: sudo pip install yamllint
       - name: Run YAMLLint
+        shell: bash
         run: "yamllint -d '{extends: relaxed, rules: {line-length: disable, trailing-spaces: disable}}' ."