Fix build with Go v1.22.1, liboqs v0.10.0

[cipherboy]

This fixes the build with newer toolchain, liboqs versions:

• liboqs v0.10.0 drops support for the NIST KAT Random source in https://github.com/open-quantum-safe/liboqs/commit/cc453db4a6e02d97bf5fc974840ace881ffa6da1 from the public API.

• This also fixes some places in the test suite where go test ./... fails due to calling string(...) on Go 1.22.1:

  > conversion from int to string yields a string of one rune, not a string of digits (did you mean fmt.Sprint(x)?)

[cipherboy]

Thank you @vsoftco!