CLD-7841 Optimize E2E testing costs (#27883)

* Utilize free runners for E2E tests, report back to PR on run completion
* Increase test stability on smaller instances
* Merge worker reports
* merge start+prepare steps
* upgrade keycloak
* increase test timeouts
* Add video recording to report artifacts

Co-authored-by: Saturnino Abril <5334504+saturninoabril@users.noreply.github.com>

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Co-authored-by: Saturnino Abril <5334504+saturninoabril@users.noreply.github.com>

e2e-tests/README.md

@@ -55,7 +55,7 @@ Notes:
   * If you need to introduce variables that you want to control from `.ci/env`: you need to update the scripts under the `.ci/` dir and configure them to write the new variables' values over to the appropriate `.env.*` file. In particular, avoid defining variables that depend on other variables within the docker-compose override files: this is to ensure uniformity in their availability and simplifies the question of what container has access to which variable considerably.
   * Exceptions are of course accepted wherever it makes sense (e.g. if you need to group variables based on some common functionality)
 - The `publish-report` Make target is meant for internal usage. Usage and variables are documented in the respective scripts.
-- `make start-server` won't cleanup containers that don't change across runs. This means that you can use it to emulate a Mattermost server upgrade while retaining your database data by simply changing the `SERVER_IMAGE` variable on your machine, and then re-runing `make start-server` (and `make prepare-server` if you intend to run cypress again, since its container is also recreated). But this also means that if you want to run a clean local environment, you may have to manually run `make stop` to cleanup any running containers and their volumes, which include e.g. the database.
+- `make start-server` won't cleanup containers that don't change across runs. This means that you can use it to emulate a Mattermost server upgrade while retaining your database data by simply changing the `SERVER_IMAGE` variable on your machine, and then re-running `make start-server`. But this also means that if you want to run a clean local environment, you may have to manually run `make stop` to cleanup any running containers and their volumes, which include e.g. the database.
 
 ##### For code changes:
 * `make fmt-ci` to format and check yaml files and shell scripts.