Migrate from RFC2896 to RFC3986

[JamieMagee]

Code improvement description

Ruby 3.4 migrated URI::DEFAULT_PARSER from RFC2396¹ to RFC3986², so as part of the Ruby 3.4 upgrade we changed our parser from DEFAULT_PARSER (implicitly RFC2396) to explicitly RFC2396. However, in the long term we should migrate to RFC3986. RFC3986 is simpler, less ambiguous, and stricter about parsing URIs.

Footnotes

1. https://datatracker.ietf.org/doc/html/rfc2396 ↩

2. https://datatracker.ietf.org/doc/html/rfc3986 ↩