feat: Switch Docker CI/CD to main branch & release v0.3.9

- Updated the Docker CI/CD workflow to trigger on pushes to the main branch, aligning with standard Git flow practices for production deployment.
- Advanced project version to 0.3.9, marking a new release with consolidated features and bug fixes.

This adjustment ensures that the Docker images are built and deployed in a more streamlined manner, reflecting our shift towards a unified branching strategy for releases. The version bump signifies the stabilization of new functionalities and enhancements for broader usage.

.forgejo/workflows/docker-latest.yml

@@ -3,7 +3,7 @@ name: Docker CI/CD
 on:
   push:
     branches:
-      - "docker"
+      - "main"
 
 jobs:
   docker:

pyproject.toml

@@ -7,7 +7,7 @@ allow-direct-references = true
 
 [project]
 name = "matrix-gptbot"
-version = "0.3.9.dev0"
+version = "0.3.9"
 
 authors = [
   { name="Kumi Mitterer", email="gptbot@kumi.email" },