chore(dependabot): group Docker updates and enable uv dependency management (#7403)

Organize Docker image updates into logical groups (ubuntu,
eclipse-temurin, gradle, uv) to reduce dependency update noise. Add uv
package manager support for the Python engine with weekly update
schedule.


---

## 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/devGuide/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/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### 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 run `task check` to verify linters, typechecks, and tests
pass
- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#7-testing)
for more details.

.github/dependabot.yml

@@ -37,6 +37,19 @@ updates:
     cooldown:
       default-days: 7
     rebase-strategy: "auto"
+    groups:
+      ubuntu:
+        patterns:
+          - "ubuntu"
+      eclipse-temurin:
+        patterns:
+          - "eclipse-temurin"
+      uv:
+        patterns:
+          - "ghcr.io/astral-sh/uv"
+      gradle:
+        patterns:
+          - "gradle"
 
   - package-ecosystem: github-actions
     directory: /
@@ -163,3 +176,11 @@ updates:
     cooldown:
       default-days: 7
     rebase-strategy: "auto"
+
+  - package-ecosystem: "uv"
+    directory: "/engine"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7
+    rebase-strategy: "auto"