[x] remove feature="next" gates guarding protocol 21 functionality (note: this is not allfeature="next" gates, some test the very concept of next-ness and should remain)
[ ] defer to next PR: ~bump workspace version to 21.0.0~
[ ] defer to next PR: ~remove feature="unstable-next-api" gates~
[x] run observations for protocol 21
[x] modify CI to run tests twice, once with TEST_PROTOCOL=20 and once with TEST_PROTOCOL=21
[x] modify recent VMCaller-using secp256r1 tests to go through the env now that it supports those host functions
This is now ready to merge. Does the following:
feature="next"gates guarding protocol 21 functionality (note: this is not allfeature="next"gates, some test the very concept of next-ness and should remain)feature="unstable-next-api"gates~