Standardize SDK licenses on MIT

[chadwhitacre]

Our docs say MIT is our standard license for SDKs. Let's make that real. This is coming up now because a new SDK took a cue from sentry-javascript and ended up with the wrong license.

Here are the SDKs on https://open.sentry.io/structure/ that aren't MIT:

• chore: Standardize SDKs on MIT License sentry-javascript#5993
• Switch to MIT license sentry-php#1471
• Switch to MIT license sentry-python#1908
• Switch to MIT license sentry-laravel#654
• Switch to MIT license sentry-symfony#697
• sentry-go
  • Switch to MIT license sentry-go#583
  • Correct copyright holder name sentry-go#584
  • Update license in README sentry-go#585

┆Issue is synchronized with this Jira Epic by Unito

[chadwhitacre]

Going with [initial pub] for copyright year since that is status quo, in future we should try to get to [initial pub]-[current release] but that requires automation in many projects so out of scope here.

[Lms24]

Just saw the PR in the JS repo
@chadwhitacre I suppose we should also change this in the (coming-soon) unplugin? Just asking b/c it's technically not an SDK but rather something like a utility for sourcemaps upload

[chadwhitacre]

@Lms24 Seems reasonable, yes. :)