build(deps): bump submodules/rest-api-specs from c68421b to `2d4992…

…b` (#4539)

Bumps [submodules/rest-api-specs](https://github.com/Azure/azure-rest-api-specs) from `c68421b` to `2d4992b`.
- [Release notes](https://github.com/Azure/azure-rest-api-specs/releases)
- [Commits](Azure/azure-rest-api-specs@c68421b...2d4992b)

---
updated-dependencies:
- dependency-name: submodules/rest-api-specs
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>