Update semantic conventions to 1.22

[mladedav]

This project's semantic conventions crate defines http.status_code while semantic conventions seem to define http.response.status_code.

The crate currently uses semantic conventions 1.20 or older. List of changes between 1.20 and later is in this issue.

[michaeljohnalbers]

I took a look at this and found a few things

1. The semantic conventions used to generate the constants have been moved into their own repo. This happened as part of the 1.21 release of the specification repo.
2. The new semantic conventions repo does not have any tags/releases/etc. (as of this writing) to which the generation script can refer. And currently, according to the README, it only matches the 1.21 spec.
3. There is a new version of the Docker otel/semconvgen Docker image the script uses. That should be updated as well.

Until the issues in item 2 are rectified, I think this issue should not be worked.