Matrix-content-scanner

Support configuration options for proxy when retrieve content from homeservers.
Support optional mime-type filter for content-scanner to restrict content types.

Changes include a bug fix for a race condition between downloading scanning and deleting unencrypted files.

Added CORS header support

* Added automated testing
* Added dependency on olm v2.3.0

Fixes the docker build.
No changes from v1.2.0.

The Matrix Content Scanner is now released by Element under an AGPLv3.0 licence.

Improvements
============
- Add support for authenticated media ([https://github.com/element-hq/matrix-content-scanner-python/pull/69](https://github.com/element-hq/matrix-content-scanner-python/pull/69), [https://github.com/element-hq/matrix-content-scanner-python/pull/70](https://github.com/element-hq/matrix-content-scanner-python/pull/70), [https://github.com/element-hq/matrix-content-scanner-python/pull/73](https://github.com/element-hq/matrix-content-scanner-python/pull/73))
- Add support for MIME block list instead of allow list ([https://github.com/element-hq/matrix-content-scanner-python/pull/67](https://github.com/element-hq/matrix-content-scanner-python/pull/67))

License
============
- Change repository license to AGPL ([https://github.com/element-hq/matrix-content-scanner-python/pull/66](https://github.com/element-hq/matrix-content-scanner-python/pull/66))

Misc
============
- Switch to ruff as linter/formatter ([https://github.com/element-hq/matrix-content-scanner-python/pull/67](https://github.com/element-hq/matrix-content-scanner-python/pull/67))