Fix deploy-docs.yml content sources (#461)

* Fix deploy-docs.yml content sources

Include future branches and tags, but exclude old tags and branches
that do not contain Antora builds

* Reduce GitHub permissions to read only

.github/workflows/deploy-docs.yml

@@ -10,9 +10,7 @@ on:
     branches: docs-build
 env:
   GRADLE_ENTERPRISE_SECRET_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_SECRET_ACCESS_KEY }}
-permissions:
-  contents: write
-  actions: write
+permissions: read-all
 jobs:
   build:
     if: github.repository_owner == 'spring-projects'