ci: also build javadoc on the JDK 25 job

Extend the JDK 25 smoke to build the javadoc jar (mvn -P javadoc package,
no tests) in addition to compiling main + test sources, so javadoc is
covered on both JDK 8 and JDK 25.

Author: bluestreak01

.github/workflows/ci.yml

@@ -40,11 +40,12 @@ jobs:
         run: mvn -B -ntp -P javadoc clean install
 
   # The client is also consumed as a submodule of the main questdb repo, which
-  # builds on JDK 25. Guard against JDK 25 compile breakage here (main + test
-  # sources, both modules), but do NOT run the tests -- the parent repo runs
-  # them against a real server.
+  # builds on JDK 25. Guard against JDK 25 compile breakage (main + test
+  # sources, both modules) and confirm the javadoc jar builds on JDK 25 too
+  # (-P javadoc attaches it at the package phase). Do NOT run the tests -- the
+  # parent repo runs them against a real server.
   compile-jdk25:
-    name: Compile smoke (JDK 25)
+    name: Compile & javadoc smoke (JDK 25)
     runs-on: ubuntu-latest
     timeout-minutes: 20
     steps:
@@ -58,5 +59,5 @@ jobs:
           java-version: "25"
           cache: maven
 
-      - name: Compile main and test sources (no tests run)
-        run: mvn -B -ntp -DskipTests clean test-compile
+      - name: Compile (main + test) and build javadoc (no tests run)
+        run: mvn -B -ntp -P javadoc -DskipTests clean package