Github Actions: Remove --disable-tests

With --disable-tests, for example for Go the `make check` under `lib/go`
would only run unit tests under `lib/go/thrift` but not the unit tests
under `lib/go/test`.

Also some changes in lib/go/test/fuzz/Makefile.am so it works in both go
1.20 and 1.21 (The current state breaks in 1.21 but because of
`--disable-tests` we never noticed that).
5 files changed