This commit modifies `test-locked-requirements` to use some caching
so that we don't need to use the `update-locked-requirements` tool
everytime for checking the validity of locked requirements as it is
slow.
Fixes: #6969.
This commit renames various source requirements files like `dev.txt`,
`mypy.txt` etc to `dev.in`, `mypy.in` etc and various locked requirements
files like `dev_lock.txt`, `mypy_lock.txt` etc to `dev.txt`, `mypy.txt`
etc. This will help in emphasizing to the user that *.in are actually
input to `update-locked-requirements` tool which should be run after
updating any of these.
This commit adds a test to check if the user forgot to run
`tools/update-locked-requirements` after updating dependencies.
Modified by tabbott to disable it by default, since it takes over a
minute to run.
Fixes: #6324.
Anders Kaseorg
Harshit Bansal