ci: stop Dependabot proposing Groovy majors that TinkerPop cannot take

.github/dependabot.yml

@@ -18,6 +18,29 @@ updates:
       interval: weekly
       day: "sunday"
     open-pull-requests-limit: 20
+    ignore:
+      # Groovy's version is dictated by TinkerPop, not by ArcadeDB. It appears
+      # only in gremlin/pom.xml and gremlin-it/pom.xml; no other module in the
+      # reactor uses it. gremlin-groovy 3.8.1 is built against the Groovy 4.0.x
+      # line (TinkerPop 3.8.1 declares groovy.version 4.0.25), so Groovy 5 is a
+      # major break that cannot be adopted until TinkerPop itself moves.
+      #
+      # Only majors are ignored. ArcadeDB deliberately runs 4.0.32, ahead of
+      # TinkerPop's own 4.0.25, so 4.0.x patch and minor updates must keep
+      # flowing.
+      #
+      # ANTLR is deliberately NOT listed here despite the same TinkerPop
+      # coupling. antlr4.version is declared per-module with two different
+      # intents: gremlin/pom.xml pins 4.9.1 because gremlin-language ships a
+      # parser generated by the ANTLR 4.9.1 tool, and ANTLR 4.10 changed the
+      # serialized ATN format, so a 4.13 runtime cannot read it. engine/pom.xml
+      # independently tracks the latest (4.13.2) for its own grammar. Dependabot
+      # ignore rules match dependency coordinates, not modules, and gremlin's
+      # frozen 4.9.1 sits below the engine's current 4.13.2, so any range that
+      # blocked the gremlin bump would silently freeze the engine too. The
+      # gremlin ANTLR PR is closed by hand instead.
+      - dependency-name: "org.apache.groovy:*"
+        update-types: ["version-update:semver-major"]
 
   - package-ecosystem: "github-actions"
     directory: "/"