[CI] Set slow build timeout to 2 hours.

Author: vyazelenko

.github/workflows/slow.yml

@@ -32,7 +32,7 @@ jobs:
   property-tests:
     name: Property tests
     runs-on: ubuntu-24.04
-    timeout-minutes: 180
+    timeout-minutes: 120
     strategy:
       matrix:
         java: [ '21' ]