Upgrade Gradle to 8.14 in CI Workflows and Gradle Wrapper (#3425)

# Description of Changes

This pull request upgrades the Gradle build system from version 8.12 to
8.14 across the Stirling-PDF project to enhance build stability,
compatibility, and performance. The changes include:

- **What was changed**:
- Updated the Gradle wrapper version in
`gradle/wrapper/gradle-wrapper.properties` from `8.12` to `8.14`.
- Modified the `tasks.wrapper` configuration in `build.gradle` to
specify `gradleVersion = "8.14"`.
- Updated Gradle version references in GitHub Actions workflows
(`multiOSReleases.yml`, `push-docker.yml`, `releaseArtifacts.yml`) from
`8.12` to `8.14` to ensure consistent CI/CD builds.

- **Why the change was made**:
- Gradle 8.14 includes bug fixes, performance improvements, and enhanced
compatibility with newer JDK versions (e.g., Java 17 and 21, as
supported by Stirling-PDF).
- Ensures alignment with the latest Gradle features and security
patches, reducing potential build issues in development and CI/CD
environments.
- Supports the project's recommendation to use newer JDK versions (e.g.,
Java 21) and improves integration with the Foojay Toolchains Plugin.

- **Challenges encountered**:
- Verified compatibility of Gradle 8.14 with existing plugins (e.g.,
`org.springframework.boot`, `org.sonarqube`, `com.diffplug.spotless`) to
ensure no breaking changes.
- Tested CI/CD workflows to confirm that the updated Gradle version does
not introduce failures in build, test, or deployment pipelines.
- Ensured the Gradle wrapper distribution URL is correctly updated to
avoid download issues.


---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] 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)
- [x] I have performed a self-review of my own code
- [x] 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)

- [x] 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.

.github/workflows/multiOSReleases.yml

@@ -70,7 +70,7 @@ jobs:
 
       - uses: gradle/actions/setup-gradle@06832c7b30a0129d7fb559bcc6e43d26f6374244 # v4.3.1
         with:
-          gradle-version: 8.12
+          gradle-version: 8.14
 
       - name: Generate jar (With Security=${{ matrix.enable_security }})
         run: ./gradlew clean createExe
@@ -158,7 +158,7 @@ jobs:
 
       - uses: gradle/actions/setup-gradle@06832c7b30a0129d7fb559bcc6e43d26f6374244 # v4.3.1
         with:
-          gradle-version: 8.12
+          gradle-version: 8.14
 
       # Install Windows dependencies
       - name: Install WiX Toolset