Bump version to 2.3.0

Bump version to 2.3.0

Update sccache cache key

Update sccache cache key

Bump version to 2.1.0

Bump version to 2.1.0

ZKVM-1377: Release 3.0: Bump versions for rc-1 (#3157)

bump versions in preparation for patch release

Bump version numbers to fix 1.2 build and backports (#3053)

This version bump covers backports to `risc0-circuit-rv32im` and
`risc0-build`.

Also bump the major versions of crates where their risc0 dependencies
have had a major version bump. This should allow us to yank the `1.4`
versions of these crates and fix the 1.2 build.

bump version to 1.2.6 (#3033)

This PR bumps the version to 1.2.6. This new version enables risc0-build
to use toolchains 1.85 and greater.