Trezorlib fixes

[grdddj]

Trying to solve some new issues with trezorlib I found recently when integrating new emulators into trezor-user-env.

1. protobuf.py had # type: ignore [Type ["Unknown | None"]], which causes mypy to flag this as a syntax error in any project that uses trezorlib ... example fail in our CI: https://github.com/trezor/trezor-user-env/actions/runs/13370973357/job/37339166006?pr=290

• I found out that it is fine with other type: ignores, and that the issue disappears when removing the inner [] ... mypy seems to have issues with this

2. Connected with transport/bridge.py - call_bridge is sending a POST request to bridge URL, but with no timeout. Just last week, with new release emulators, it started happening that the bridge just did not anwer at all. It is strange that it happened just now, with new emulators - we suspect something is different/new in new (2.8.7 and higher) emulators (one other clue is not being able to run Shamir backup flow built for older emulators).

[github-actions]

core UI changes	device test	click test	persistence test
T2T1 Model T	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3B1 Safe 3	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3T1 Safe 5	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
All	main(screens)

[grdddj]

Deleted the timeout-setting code in favor of #4655