Go Version Mismatch

[sneelam20]

Bookworm slave docker uses go1.15 for FIPS builds and go1.19 for normal builds. This can lead to unexpected compilation errors. Single version should have been picked, preferably the latest one (go1.21.x). sonic-gnmi & sonic-mgmt-framework dockers still use bullseye & buster toolchains respectively; both are on go1.15.

Reference: https://github.com/sonic-net/sonic-buildimage/blob/master/sonic-slave-bookworm/Dockerfile.j2#L453C8-L453C21