Fix GitHub Actions test failures by replacing deprecated openjdk:11-jdk image

The openjdk:11-jdk Docker image has been deprecated and removed from Docker Hub,
causing test failures in test-container-x64 jobs across all Python versions.

Replace openjdk:11-jdk with eclipse-temurin:11-jdk, which is the official
successor and actively maintained by the Eclipse Foundation. This is consistent
with other JDK images already used in the test suite.

Fixes:
- test_collect_default_jvm_flags[hotspot-jdk-11-expected_flags1-True]
- test_collect_cmdline_and_env_jvm_flags[hotspot-jdk-11-expected_flags1-True--XX:SelfDestructTimer=5--XX:+PrintCodeCache]

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: mlim19

tests/conftest.py

@@ -290,7 +290,7 @@ def application_pid(
     "java": {
         "": {},
         "hotspot-jdk-8": {},  # add for clarity when testing with multiple JDKs
-        "hotspot-jdk-11": dict(buildargs={"JAVA_BASE_IMAGE": "openjdk:11-jdk"}),
+        "hotspot-jdk-11": dict(buildargs={"JAVA_BASE_IMAGE": "eclipse-temurin:11-jdk"}),
         "j9": dict(buildargs={"JAVA_BASE_IMAGE": "adoptopenjdk/openjdk8-openj9"}),
         "eclipse-temurin-latest": dict(buildargs={"JAVA_BASE_IMAGE": "eclipse-temurin:latest"}),
         "zing": dict(dockerfile="zing.Dockerfile"),