[mod] CI: exclude SearXNG checker and build & deploy of online docs (#4875)

checker.yml

1. The checker is not yet of sufficient quality to allow the results of the
   check to be evaluated / we do not evaluate them ourselves.

2. The checker sends hundreds of requests to the search engines and causes
   problems there / we either overload small providers or we train their bot
   defenses to use the SearXNG signature.

documentation.yml

Building the documentation and deploying it on GH-docs of a clones (GH forks) is
generally not desirable either --> We have >2k clones, but we only need one
up-to-date documentation and that is the one from the master branch of the
searxng/searxng repo.

If search engines like Google start linking to the documentation in the clones,
SearXNG users may no longer find the original documentation or be lost in the
flood of options.

Related:

- https://github.com/searxng/searxng/issues/4847

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

.github/workflows/checker.yml

@@ -19,6 +19,7 @@ env:
 
 jobs:
   search:
+    if: github.repository_owner == 'searxng' || github.event_name == 'workflow_dispatch'
     name: Search
     runs-on: ubuntu-24.04-arm
     steps:

.github/workflows/documentation.yml

@@ -23,6 +23,7 @@ env:
 
 jobs:
   release:
+    if: github.repository_owner == 'searxng' || github.event_name == 'workflow_dispatch'
     name: Release
     runs-on: ubuntu-24.04-arm
     permissions: