chore(deps): update rstest requirement from 0.18 to 0.21 #723

Job	Run time
Run checks (macos-12)	1m 39s
Run checks (windows-latest)	2m 19s
Run checks (ubuntu-latest)	49s
Build library (iOS) (aarch64-apple-ios)	3m 54s
Build library (Android) (aarch64-linux-android)	3m 45s
Build library (iOS) (aarch64-apple-ios-sim)	3m 54s
Run Test Suite	5m 29s
Build library (Android) (armv7-linux-androideabi)	3m 38s
Build library (linux-aarch64, ubuntu-latest, libindy_vdr.so, aarch64-unknown-linux-gnu, true)	3m 17s
Build library (iOS) (x86_64-apple-ios)	3m 14s
Build library (Android) (i686-linux-android)	3m 39s
Build library (linux-x86_64, ubuntu-latest, libindy_vdr.so, x86_64-unknown-linux-gnu, true)	2m 58s
Build library (Android) (x86_64-linux-android)	3m 43s
Build library (darwin-universal, macos-12, libindy_vdr.dylib, darwin-universal, beta)	4m 46s
Build library (windows-x86_64, windows-latest, indy_vdr.dll, x86_64-pc-windows-msvc)	3m 47s
Create library (Android)	11s
Create iOS xcframework	28s
Create iOS and Android release assets	0s
Build and Test JavaScript wrapper	1m 38s
Build and test Python wrapper (linux-aarch64, 3.8)	21s
Build and Test Go wrapper	14s
Build and test Python wrapper (linux-x86_64, 3.8)	27s
Build and test Python wrapper (darwin-universal, 3.8)	35s
Build and test Python wrapper (windows-x86_64, 3.8)	52s
	55m 37s

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