Optimize PR checks

[mlqn]

Description

Optimization of PR checks to reduce execution time and decrease resource consumption.

• Removed build-image-on-pr.yaml workflow as Docker images are already built by Playwright tests
• Removed Building job from frontend-unit-tests.yml workflow as the solution is already built by Playwright tests
• Removed Build all images job from run-playwright-on-pr.yaml as the solution is already built during setup
• Removed Stop compose file job from run-playwright-on-pr.yaml as it's already stopped when the VM is stopped
• Removed dotnet build from Dockerfile as the backend is already built by dotnet publish
• Fixed the typecheck command to prevent it from running multiple times. This is a quick fix, we should fix the tsconfig.json files to make them work per workspace (see: Fix typecheck command #13031)
• Optimized Dockerfile layer caching by separating the copying of package.json and yarn.lock files
• Added layer caching to the docker-compose command used during Playwright tests
• Added a concurrency control on run-playwright-on-pr.yaml to stop previous running instances
• Added the --cache flag to the eslint command to only check changed files
• Added the --changedSince flag to the Jest command to only run tests impacted by changes in a PR
  We still run all the tests when merging a PR into main, as it seems that sometimes this command does not execute all the impacted files.

PR checks

BEFORE	AFTER

Docker layer caching

BEFORE	AFTER

Related Issue(s)

• Remove duplicated PR checks #12474
• Caching yarn packages when building the Docker image #12387

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)

[mlqn]

Will be solved by #13032