mozjs-sys-v140.10.1-0: Security bump to 140.10.1 (#745)

Bump SpiderMonkey to 140.10.1 (changeset:
[a24e9e115e02794f72dab9ef6081244403b0183a](https://github.com/servo/mozjs/releases/download/mozjs-source-a24e9e115e02794f72dab9ef6081244403b0183a))

Changes the base mozjs-sys version number to 140.10.1, dropping the `0`
major, to make space for the patch version of upstream Spidermonkey. We
still use a `-<our_version>` suffix, meaning from cargos point of view
all releases are pre-releases, hence nothing changes on the semver side
of things.

Also change the update script to only commit `mozjs-sys/mozjs`, since
nothing else should be committed.

Testing: Covered by existing tests

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Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>