This reverts commit bf7f957af2.
We still have to manually install it for now but we don't have to fuck around
with env vars anymore. github actions still defaults to go 1.15 [1]. Whatever.
[1]
```
ls -lisah $(which go)
108022 0 lrwxrwxrwx 1 root root 42 Mar 18 22:15 /usr/bin/go ->
/opt/hostedtoolcache/go/1.15.10/x64/bin/go
```
b9f05878fa