Add GIT_OPTIONAL_LOCKS=0 to all Git calls

[mattseddon]

Related to #4111 & iterative/dvc#9749

Docs

GIT_OPTIONAL_LOCKS

If this Boolean environment variable is set to false, Git will complete any requested operation without performing any optional sub-operations that require taking a lock. For example, this will prevent git status from refreshing the index as a side effect. This is useful for processes running in the background which do not want to cause lock contention with other operations on the repository. Defaults to 1.

[codeclimate]

Code Climate has analyzed commit 62f38f9 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (85% is the threshold).

This pull request will bring the total coverage in the repository to 95.3% (0.0% change).

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