[CI] [Meta] CI Improvements

[Dinonard]

There are a lot of areas for improvement in Astar CI.
More automated checks, well adapted test framework for RPC testing, automated release & check actions, etc.

Purpose of this meta ticket is to keep track of all the ideas & work items in one place.
Feel free to propose additional items in the comments or just open up a new issue with the proper description.

Tests

• [CI] CI Test For Block Sync #1014
• [CI] PoV Integration Tests #1016

Benchmarks

• [CI] Benchmark multiple runtimes at once #1052

PR

• [CI] Improve compile & check part of the CI #1063

Build & Test

• [CI] - Run tests and/or compilation separately for each workspace crate #1213