This prep commit moves the 'rename_indexes_constraints'
function to 'lib/migrate' as we're going to re-use it for
the 'UserHotspot' to 'OnboardingStep' table rename operation.
In general, this function would be helpful in migrations
involving table rename operations, subject to the caution
mentioned in the function via comments.
Letting the clock tick without a reason introduces the
possibility of nondeterministic test failures depending on the execution
time. The default value when not specified is tick=True, which makes it
easy to miss.
The rule doesn't prohibit setting tick=True, as perhaps there will be
tests wanting to use that feature on purpose, but such a test should
explicitly set it to make the intent clear.
Semgrep 0.118.0 changed the default of --scan-unknown-extensions to
false. It also seems that it no longer respects --lang (or never
did), so rename the config file to reflect that it only includes
Python rules, to make it clear that additional languages will require
separate config files.
Signed-off-by: Anders Kaseorg <anders@zulip.com>