add bash as shell

.gitea/workflows/deploy-ci.yaml

@@ -15,8 +15,8 @@ jobs:
 
     steps:
       - name: Fetch CI template via Gitea API
+        shell: bash
         run: |
-          # get the template file (base64)
           resp=$(curl -sSL \
             -H "Authorization: token $TOKEN" \
             "$GITEA_API/repos/osc/skins-template/contents/$TEMPLATE_PATH?ref=main")
@@ -24,6 +24,7 @@ jobs:
           echo "TEMPLATE_B64=$template_b64" >> $GITHUB_ENV
 
       - name: Fetch valid user repositories
+        shell: bash
         run: |
           page=1
           per_page=50
@@ -88,6 +89,7 @@ jobs:
           echo "VALID_REPOS_FILE=$valid_repos_file" >> $GITHUB_ENV
 
       - name: Update CI via Gitea API
+        shell: bash
         run: |
           mapfile -t repos < "$VALID_REPOS_FILE"
           total=${#repos[@]}
@@ -128,4 +130,5 @@ jobs:
           done
 
       - name: Cleanup
+        shell: bash
         run: rm -f "$VALID_REPOS_FILE"