refactor: simplify error handling in Docker workflow by using set -eu

.gitea/workflows/docker-build-push.yml

@@ -29,7 +29,7 @@ jobs:
         env:
           GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
-          set -euo pipefail
+          set -eu
           apk add --no-cache git ca-certificates
           REF="$GITHUB_REF"
           REPO_URL="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY"
@@ -50,7 +50,7 @@ jobs:
           IMAGE_NAME_VAR: ${{ vars.IMAGE_NAME }}
           GITEA_REGISTRY_VAR: ${{ vars.GITEA_REGISTRY }}
         run: |
-          set -euo pipefail
+          set -eu
           # Derive registry/namespace/image from environment provided by runner
           # GITHUB_REPOSITORY is like "owner/repo"
           OWNER=${GITHUB_REPOSITORY%%/*}
@@ -82,36 +82,36 @@ jobs:
           OWNER: ${{ steps.vars.outputs.owner }}
           IMAGE: ${{ steps.vars.outputs.image }}
         run: |
-          set -euo pipefail
+          set -eu
           IMAGE_FULL="$REGISTRY/$OWNER/$IMAGE"
 
           REF="$GITHUB_REF"
           SHA_SHORT=$(echo "$GITHUB_SHA" | cut -c1-8)
-          TAGS=()
+          TAGS=""
 
           case "$REF" in
             refs/heads/*)
               BRANCH=${REF#refs/heads/}
               # latest for main/master
               if [ "$BRANCH" = "main" ] || [ "$BRANCH" = "master" ]; then
-                TAGS+=("latest")
+                TAGS="${TAGS} latest"
               fi
               # branch tag
               SAFE_BRANCH=$(echo "$BRANCH" | tr '/' '-' )
-              TAGS+=("$SAFE_BRANCH")
+              TAGS="${TAGS} ${SAFE_BRANCH}"
               ;;
             refs/tags/*)
               TAG=${REF#refs/tags/}
-              TAGS+=("$TAG")
+              TAGS="${TAGS} ${TAG}"
               ;;
           esac
 
           # always include short sha
-          TAGS+=("$SHA_SHORT")
+          TAGS="${TAGS} ${SHA_SHORT}"
 
           # Build -t args
           TAG_ARGS=""
-          for t in "${TAGS[@]}"; do
+          for t in $TAGS; do
             TAG_ARGS="$TAG_ARGS -t $IMAGE_FULL:$t"
           done
 
@@ -126,7 +126,7 @@ jobs:
 
       - name: Ensure buildx builder
         run: |
-          set -euo pipefail
+          set -eu
           docker buildx inspect dindbuilder >/dev/null 2>&1 || docker buildx create --name dindbuilder --driver docker-container --use
 
       - name: Build and push (linux/amd64)
@@ -135,7 +135,7 @@ jobs:
           IMAGE_FULL: ${{ steps.tags.outputs.image_full }}
           TAG_ARGS: ${{ steps.tags.outputs.tag_args }}
         run: |
-          set -euo pipefail
+          set -eu
           echo "Building $IMAGE_FULL with tags: $TAG_ARGS"
           docker buildx build \
             --platform linux/amd64 \