t/100-python.t: Perform a `git reset` at test's end
t/100-python.t: Perform a `git reset` at test's end

Ensure we reset the staging area as a teardow/cleanup operation.
Otherwise, our JavaScript test (which runs after this one by default)
will be working with a dirty staging area and its test will by
consequence not pass.

teddywing/git-hook-pre-commit-python-javascript-syntax-linter,teddywing/git-hook-pre-commit-python-javascript-syntax-linter,teddywing/git-hook-pre-commit-python-javascript-syntax-linter,teddywing/git-hook-pre-commit-python-javascript-syntax-linter