extension: bump the submodule past the lint fixes

[Ryanmello07]

The extension leg of CI has been red since it was added. It is not the
workflow's fault — this repo pins extension at 8f75f07d8b, which predates
urnetwork/extension#36.
npm run lint fails at that commit with 12 errors.

#36 fixed all twelve and merged, but a submodule pin does not follow a merge in
the component repo, so CI kept building the pre-fix tree and kept reporting the
same twelve errors.

What this picks up

9f4d6fdf6  ci: build and test the extension on push
0f912dec0  ci: report lint without gating build and test
c793894d5  ci: add timeout and concurrency; correct the lint comment
4e1c494c7  fix(connect): stop writing the SDK callback refs during render
fbc4ec63f  fix(types): replace the nine `any` casts and drop an unused list
660e05e39  Merge pull request #36 from urnetwork/fix/lint-errors

4e1c494c7 is the one that matters beyond lint: refs were being assigned during
render, feeding a ConnectionManager built once with [] deps that invokes the
auth thunk from timers — so a discarded render could publish a callback into a
live long-lived object.

A pattern, not a one-off

This is the second time a stale pin has produced a red leg that looked like a
CI defect. The Arch package leg was the first: it warned and skipped for two runs
because packaging/make-arch.sh did not exist at the pinned linux commit.

Now that every component repo builds and tests itself on push, this repo's pins
are the thing most likely to go stale — and a stale pin always presents as a
failure in whatever that pin feeds, not as "the pin is old". Worth considering a
periodic pin-bump job so CI keeps testing what the components actually ship.