Add CI filter for individual community builds

Author: nicolasstucki

.github/workflows/ci.yaml

@@ -256,6 +256,7 @@ jobs:
            github.event_name == 'pull_request'
            && !contains(github.event.pull_request.body, '[skip ci]')
            && !contains(github.event.pull_request.body, '[skip community_build]')
+           && !contains(github.event.pull_request.body, '[skip community_build_a]')
          )
          || (
            github.event_name == 'workflow_dispatch'
@@ -303,6 +304,7 @@ jobs:
            github.event_name == 'pull_request'
            && !contains(github.event.pull_request.body, '[skip ci]')
            && !contains(github.event.pull_request.body, '[skip community_build]')
+           && !contains(github.event.pull_request.body, '[skip community_build_b]')
          )
          || (
            github.event_name == 'workflow_dispatch'
@@ -350,6 +352,7 @@ jobs:
            github.event_name == 'pull_request'
            && !contains(github.event.pull_request.body, '[skip ci]')
            && !contains(github.event.pull_request.body, '[skip community_build]')
+           && !contains(github.event.pull_request.body, '[skip community_build_c]')
          )
          || (
            github.event_name == 'workflow_dispatch'