fix openapi json schema integrity

[jonchurch]

There is a missing closing brace around the market/supply endpoint, making the JSON invalid. That also led to a duplicate parameters key/value.

Can check the formatting of the original w/ jq . reference/SpaceTraders.json

There was a seemingly unused application/xml definition as well for that endpoint. For the generators, 3.1.1 seems to want to have a license identifier (although that should be optional so far as I know) so I added it.

The openapi-generator-cli w/ ts client doesnt like 3.1.1 btw, so to get a client generated for myself I downgraded the schema to 3.0.3

But this PR just fixes the schema integrity for what was merged in, with the additional changes of adding the identifier and removing the application/xml object.

[jonchurch]

There still seems to be something off about the market/supply endpoint's defintion of the exportToImportMap

string isnt a valid property name for the generators, but I haven't been able to create a good defintion that just uses the TradeSymbol model for possible property names.

This shouldnt impact generation though

[jonchurch]

This was fixed in a8e4c6f