feat: add merge workflow

[Emnaghz]

Motivation

This workflow automates the process of building and pushing Docker images for different parts of the project when changes are pushed to the main branch or triggered manually.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (Storybook)
• I have added unit tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[marrouchi]

A general remark, I think we can may do the setup of docker and login once to build all the images.

[Emnaghz]

In the updated workflow, I've optimized the process by separating the tasks into two distinct jobs:

Job 1: Path Filtering
It filters the paths to determine which parts of the codebase have changed and outputs these results to be used by subsequent jobs.

Job 2: Build and Push Docker Images
This job handles the setup of the building environment, the authentication as well as the conditional builds.

Explanation:
When I separated the Docker Hub login process and the environment setup from the build and push steps, I encountered several issues. Each job in GitHub Actions is executed in a separate environment, which means that the authentication status as well as the env setup wasn't shared between other jobs and resulted in many errors.

To address this, I had to ensure that the Docker Hub login and environment setup steps were completed in the same job as the build and push operations.

[marrouchi]

I forgot that we need to build the docker image for nlu as well "hexabot-nlu"

[marrouchi]

Suggested change

	tags: ${{ secrets.DOCKERHUB_USERNAME }}/hexabot-frontend:latest
	tags: hexastack/hexabot-ui:latest

[marrouchi]

Suggested change

	context: ./
	context: ./widget

I think we need to set the widget context like this. Can you push and check ?

[marrouchi]

Suggested change

	tags: ${{ secrets.DOCKERHUB_USERNAME }}/hexabot-api:latest
	tags: hexastack/hexabot-api:latest