Test cleanup, JVM GC and api (#2787)

# Description of Changes

Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: a <a>

Dockerfile

@@ -25,7 +25,13 @@ LABEL org.opencontainers.image.keywords="PDF, manipulation, merge, split, conver
 # Set Environment Variables
 ENV DOCKER_ENABLE_SECURITY=false \
     VERSION_TAG=$VERSION_TAG \
-    JAVA_TOOL_OPTIONS="$JAVA_TOOL_OPTIONS -XX:MaxRAMPercentage=75" \
+    JAVA_TOOL_OPTIONS="-XX:+UnlockExperimentalVMOptions \
+    -XX:MaxRAMPercentage=75 \
+    -XX:InitiatingHeapOccupancyPercent=20 \
+    -XX:+G1PeriodicGCInvokesConcurrent \
+    -XX:G1PeriodicGCInterval=10000 \
+    -XX:+UseStringDeduplication \
+    -XX:G1PeriodicGCSystemLoadThreshold=70" \
     HOME=/home/stirlingpdfuser \
     PUID=1000 \
     PGID=1000 \