spec change: support variance on parameter specification and type variable tuple

[KotlinIsland]

python/typing issue with various links: python/typing#2215

• Carl
• Dave
• Jelle
• Rebecca
• Joren

[carljm]

@JukkaL can you take a look here?

[KotlinIsland]

@JukkaL are you able to check this please

[KotlinIsland]

@jorenham are you able to review this please

[carljm]

@KotlinIsland We decided that existing issues like this which are all ready to go apart from Jukka review can just move ahead, they don't have to wait for @jorenham (though of course Joren is also welcome to review!). If you rebase the spec/conformance PR I'll take one more look at it and merge it if all looks good. Thanks for your patience, and sorry for the wait.

[jorenham]

@jorenham are you able to review this please

done :)

[JelleZijlstra]

Thanks for your proposal! We can close this as accepted, though the python/typing PR still has some unresolved feedback. We'll merge this once we're satisfied with the spec and conformance changes.