Pulled in latest upstream changes for improved standards-compliance

[uberbrady]

The original version of the laravel-scim-server package that we use for our SCIM support has made a few updates that I wanted to take in. Furthermore, our SCIM support with the new .env var for SCIM_STANDARDS_COMPLIANCE had a few bugs that dropped 500-series errors. So this change goes along with those updates to our fork of the library, so it uses the new config variable (upstream chose a different config variable name), and the new functionality (which is much less hacky than what I built before).

[what-the-diff]

• The key "standards_compliance" was changed to "omit_main_schema_in_return".
• The default value of the new key is set by env('SCIM-STANDARDS-COMPLIANCE', false).