CI: prevent Dependabot from upgrading LSP4j

Author: ForNeVeR

.github/dependabot.yml

@@ -1,14 +1,17 @@
-# Dependabot configuration:
-# https://docs.github.com/en/free-pro-team@latest/github/administering-a-repository/configuration-options-for-dependency-updates
-
+# https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#ignore
 version: 2
 updates:
-  # Maintain dependencies for Gradle dependencies
   - package-ecosystem: "gradle"
     directory: "/"
     schedule:
       interval: "daily"
-  # Maintain dependencies for GitHub Actions
+    ignore:
+      # Prevent Dependabot from updating LSP4J to new versions
+      # TODO: Remove this block after updating to the new PSES
+      - dependency-name: "org.eclipse.lsp4j:org.eclipse.lsp4j"
+        update-types:
+          - version-update:semver-major
+          - version-update:semver-minor
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule: