Skip slow server tests in the pre-commit hook

The server test suite now runs against embedded PostgreSQL and takes
~10 minutes per run — too slow to gate every commit. The hook now only
runs `desktopTest`. Run `:server:test` manually before pushing, or rely
on CI to catch server-side regressions.

.gitHooks/pre-commit

@@ -3,8 +3,9 @@
 # Change to the root directory of your project
 #cd /path/to/your/project/root
 
-# Run the Gradle test task
-./gradlew desktopTest server:test
+# Run fast test suites. `:server:test` is excluded because the embedded
+# PostgreSQL make it too slow for every commit.
+./gradlew desktopTest
 
 # Check the exit code of the test task
 if [ $? -ne 0 ]; then