Use match to get code signing certificates

[magkue]

This PR adds the retrieval of the code signing certificate via Fastlane match.

Certs are stored encrypted in a gitlab repository and managed automatically by Fastlane. The cert is shared by multiple build agents across multiple platforms. For this to be used with GitHub actions a workflow needs to be configured. The necessary environment vars (all prefixed with IOS_) are set as organization secrets. The workflow additionally should export a, for all workflows unique, BUILD_NUMBER. A example workflow for building and releasing from gitlab is linked in this PR.

I also added a new self-hosted runner that needs to be used for the workflow called ls1Agent-mac-2.ase.cit.tum.de with the label "macOS".

Workflow example from GitLab:

stages:
  - Build 🛠️
  - Release 🚀

variables:
  LANG: "en_US.UTF-8"
  LANGUAGE: "en_US.UTF-8"
  LC_ALL: "en_US.UTF-8"

build:
  stage: Build 🛠️
  script:
    - bundle update
    - bundle exec fastlane build
  artifacts:
    expire_in: 1 week
    paths:
      - ./build/*/*.ipa
      - ./build/*/*.dSYM.zip
  tags:
    - macos

release:
  stage: Release 🚀
  script:
    - bundle exec fastlane release
  when: manual # Run the release only after manual action
  needs:
    - build
  tags:
    - macos
  only:
    - main
    - develop

[anian03]

Thank you for fixing it, this is great :D

No major objections from my side. Technically we can leave out the testing part as we currently don't have any tests, but for the future it makes sense to already have it. Do you have any objections against merging it like this, e.g. testing the TestFlight upload beforehand? The screenshots action we can do in a separate PR

[magkue]

From my side this is fine, yes the screenshots can be a separate PR. Should I merge it or do you want to do it. I would definitely squash it before the merge, as I did quite some messy commits in between.

[anian03]

Thanks! I will merge it and definitely squash :)