Gitaly rake job during source installation update from 15.3 to 15.4 fails.

Summary

Running the gitaly rake job according to the documentation fails, because it runs as as the git user, but tries to run the git make target as well (which the source installation docs do earlier, separately.

Steps to reproduce

1. Do a source install of 15.3
2. Follow the upgrade instructions to 15.4

What is the current bug behavior?

The gitaly rake job prints the output from the failing make job, where make fails in the recursively started make of git, which fails at installing the built binaries to /usr/local

What is the expected correct behavior?

The gitaly rake job finishes without an error.

Possible fixes

Removing the git target from the gitaly rake job.