fix(api): update image version handling and remove SENTRY_RELEASE property

[0x1026]

This pull request includes changes to the api/src and api/tests directories to modify how the IMAGE_VERSION is handled and to remove the SENTRY_RELEASE property. The changes ensure that the IMAGE_VERSION always starts with a 'v' prefix and simplify the configuration settings.

Configuration changes:

• api/src/config.py: Modified the check_image_version method to ensure the IMAGE_VERSION starts with a 'v' prefix. Removed the SENTRY_RELEASE property from the Settings class. [1] [2]

Usage updates:

• api/src/main.py: Updated references to SENTRY_RELEASE to use IMAGE_VERSION instead in the Sentry initialization and health check endpoint. [1] [2]

Test adjustments:

• api/tests/test_config.py: Removed assertions related to SENTRY_RELEASE and updated tests to reflect the new handling of IMAGE_VERSION with a 'v' prefix. [1] [2] [3]