This was found useful by @Bramas when building a Dockerfile of the web app
itself. See https://github.com/ente-io/ente/pull/1065.
Now, the GIT_SHA environment variable can just be undefined if we're not in a
git repository, and the code using it deals with that case explicitly.
**Tested by**
Temporarily inverted the isDevBuild flag, tehn
1. Ran the build normally and verified that the SHA continued to appear in the logs.
2. Ran the build after copying to a standalone folder without an associated git
repository and verified that the SHA was skipped without causing the build to
fail.
Sentry has a measurable impact on page load, a metric that I'm keen to
improve. Apparently by default it loses us 8-9 page speed points, though that
can be reduced to 3-4
(https://github.com/getsentry/sentry-javascript/issues/9179).
All of this is doable, but there are bigger tasks to deal with. This is not to
say that Sentry won't be useful again at some point, when we have time to deal
with it better. But right now, we discussed that it's just better to remove
Sentry instead of piling on to the sunk cost.
