1.4.0

#106 Swapped over to Ruff for linting, cleaning up some code smells:

• Providing a non-datetime object to oauth_expires_at now raises ValueError explicitly rather than using a plain assert.
• Bumped minimum supported python version to 3.10 to take advantage of some slightly nicer type checking.

#107 Added some crude type annotations (to be improved on over time).

Other housekeeping:

• 75757d9 Updated to f-strings
• 2cb4105 Tidied up the gitignore