ci(GHA): replaced set-output with GITHUB_OUTPUT (banzaicloud#4)

Reason: deprecated, will be removed in 2023-05-31.

Details: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Command: grep -R -l "::set-output" . | xargs -n 1 sed -E -i '' 's/"?::set-output name=([^:]+)::([^"]+)"?$/"\1=\2" >> $GITHUB_OUTPUT/g'

.github/workflows/docker.yml

@@ -33,7 +33,7 @@ jobs:
           if_false: latest
       - name: Determine image tag
         id: imagetag
-        run: echo "::set-output name=value::${TAG_OR_BRANCH##*/}"
+        run: echo "value=${TAG_OR_BRANCH##*/}" >> $GITHUB_OUTPUT
         env:
           TAG_OR_BRANCH: ${{ steps.refortag.outputs.value }}