Change minimum version of golang in readme

[amghazanfari]

In the readme there are two statements

1. the minimum version of go for runc is v1.21
2. if you use go v1.22 make sure it's newer than 1.22.4 due to a bug

when i use go v1.21 in Dockerfile for testing I got error

+ exec make localunittest TESTFLAGS=
rm -f libcontainer/dmz/binary/runc-dmz
go generate -tags "seccomp urfave_cli_no_docs" ./libcontainer/dmz
go: go.mod requires go >= 1.22 (running go 1.21.13; GOTOOLCHAIN=local)
make: *** [Makefile:116: runc-dmz] Error 1
make: *** [Makefile:161: unittest] Error 2

but with go v1.22 and v1.23 it was ok. so i change minimum version to 1.22.4 and delete the warning