Update seedsigner-translations submodule to latest dev (9a76a81)

[Chaitanya-Keyal]

Description

This PR updates the seedsigner-translations submodule to the latest dev commit (SeedSigner/seedsigner-translations@9a76a81).

Additionally, this PR fixes CI run failures that emerged with this submodule update. In recent changes to the seedsigner-translations repo, the compiled .mo files were removed from version control. Because the tests workflow in this repository did not have the compile_catalog step (unlike our other workflows), the .mo files were entirely absent during tests.

Additional Information / CI Changes

• Added setuptools to requirements-l10n.txt: Our translation compilation relies on setup.py, but starting in Python 3.12, setuptools is no longer bundled by default via ensurepip/venv. Adding it explicitly ensures the Python 3.12+ matrix builds succeed without throwing ModuleNotFoundError: No module named 'setuptools'.
• Compile Catalog Step: Updated tests.yml to explicitly install l10n/requirements-l10n.txt and run python setup.py compile_catalog right before executing the tests to generate the missing .mo files.
• Editable Install Mode: Changed the installation command to pip install -e . (editable mode). This ensures that the newly compiled .mo files generated directly inside the src directory are immediately available and resolvable by pytest.

All these changes make the tests workflow in this repo similar to the translations repo's workflow.

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This pull request is categorized as a:

• Other

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Checklist

I ran pytest locally

• All tests passed before submitting the PR

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I included screenshots of any new or modified screens

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I added or updated tests

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I tested this PR hands-on on the following platform(s):

• Raspberry Pi OS Manual Build

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