Tests that create temp repos call `git init` without specifying a branch.
Git then prints a 12-line "hint: Using 'master' as the name for the
initial branch..." block — every test, every run. The output drowns out
actual failures.
Set init.defaultBranch=master via GIT_CONFIG_COUNT/KEY/VALUE env vars in
script/test. This affects only subprocesses spawned by the test runner;
no change to the user's real git config.
Verified: cargo test --bin huskies emits 0 `hint:` lines after this
change, all 2732 tests still pass.
dave
3ff361bfe8