run pyupgrade

run pyupgrade

command is:

find alembic -name "*.py" | xargs pyupgrade --py37-plus --keep-runtime-typing --keep-percent-format

I'm having some weird fighting with the tools/write_pyi, where
in different runtime contexts it keeps losing "MigrationContext"
and also Callable drops the args, but it's not consisistent.
For whatever reason, under py311 things *do* work every time.
im working w/ clean tox environments so not really sure what the
change is.  anyway, let's at least fix the quoting up
around the types.

This is towards getting the "*" in the op signatures for #1130.

Change-Id: I9175905d3b4325e03a97d6752356b70be20e9fad