feat(astro): Streamline build logs

[mydea]

This streamlines astro build logs in two ways:

1. Guard all logs (except the deprecation warning) behind debug: true
2. Use the astro logger instead of console.log everywhere. This automatically prepends the message with @sentry/astro, so no need for our own prefix there - see https://docs.astro.build/en/reference/integrations-reference/#astrointegrationlogger
3. If sourceMaps: false is explicitly set by a user, we always show a short warning, and a longer warning with more context when debug: true

[Lms24]

Is this PR supposed to contain React Router and SolidStart changes as well?

[mydea]

Is this PR supposed to contain React Router and SolidStart changes as well?

oops, no, search and replace error ^^

[s1gr1d]

Suggested change

	logger.warn('Source map generation is disabled in your Astro configuration.');
	logger.warn(`Source map generation is disabled in your Astro configuration (\`${settingKey}: false\`.`);

[mydea]

I want to keep this extra compact, users can use debug: true for more information :)