Go 1.20 introduces a gocache 

On the positive side,.go 1.20 has dropped the precompiled binaries that made the container a Gigabyte in size. It also introduces a persistent caching mechanism, which needs to be prepopulated otherwise builds are getting a lot slower. 

See https://groups.google.com/g/golang-nuts/c/z_zbr3fSayc/m/NXRaZQEgBQAJ for details 