Migrate to Github Actions

[WojciechMazur]

• Remove Jenkins coordinator and related components
• Publish existing maven and Elasticsearch services via the ingress
• Migrate to GitHub actions:
  • Build plan is stored as workflow_call, can be called by other jobs
  • Build config is stored in the repo, not calculated on each build
  • Build is limited to 1000 jobs (with higher number of builds GHA web page is failing to load finished job due to internal timeouts)
  • Each stage is limited to at most 255 jobs (GHA limit for matrix entries)
  • Build plan and config are updated weekly via a scheduled updated
  • Build plan is executed weekly using the detected last version of Scala Nightly
  • Builds can be started manually with a custom version or repo/branch configuration
  • Custom build takes additional arguments allowing to specify additional or disabled scalacOptions (used only by sbt builds)
  • Each build creates artifacts containing 3 reports comparing the current version of compiler, with the results from last stable version, the last RC, and the total report including all failures (not filtering out previously failing builds)
• Raport regressions script is now using public ES instance, no longer requires forwarding k8s pod port
• Upgraded version to v0.2.1