feat: Define MSRV #17

Job	Run time
Flutter integration test on iOS (iPad (9th generation) Simulator (16.2))	12m 56s
Flutter integration test on iOS (iPhone 12 Pro Max Simulator (16.2))	16m 31s
Flutter integration test on Android (pixel, 29)	20m 31s
Flutter integration test on Android (Nexus 6, 29)	20m 51s
Dart linter	1m 35s
Codegen (macos-11)	5m 41s
Codegen (windows-2019)	7m 38s
Codegen (ubuntu-20.04)	3m 38s
Dart test with Valgrind	4m 29s
Dart test with vm service	3m 1s
Dart test on Web	4m 58s
Dart test on Web (wasm-start)	4m 8s
Flutter integration test on Linux	4m 10s
Flutter integration test on MacOS	13m 15s
Flutter integration test on Windows	9m 6s
test MSRV and specific problematic versions (nightly)	5m 3s
test MSRV and specific problematic versions (nightly-2023-06-28)	4m 52s
test MSRV and specific problematic versions (nightly-2023-07-26)	5m 5s
test MSRV and specific problematic versions (nightly-2022-07-15)	8m 16s
test MSRV and specific problematic versions (1.64)	7m 32s
Rust build and test (macos-11)	6m 20s
Rust build and test (windows-2019)	9m 13s
Rust build and test (ubuntu-latest)	5m 52s
Rust linter (1.68.0)	3m 33s
	3h 8m 14s

Provide feedback