build(deps): update protobuf requirement from >= 3.0, <3.5.0 to >= 3.0, <3.8.0

Updates the requirements on [protobuf](https://github.com/stepancheg/rust-protobuf) to permit the latest version.
- [Changelog](https://github.com/stepancheg/rust-protobuf/blob/master/CHANGELOG.md)
- [Commits](stepancheg/rust-protobuf@v3.0.0...v3.7.1)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

crates/shim-protos/Cargo.toml

@@ -51,7 +51,7 @@ required-features = ["async"]
 async-trait = { workspace = true, optional = true }
 # protobuf 3.5 introduces a breaking change: https://github.com/containerd/rust-extensions/issues/295
 # pinning to <3.5.0 until we can update the generated code
-protobuf = ">= 3.0, <3.5.0"
+protobuf = ">= 3.0, <3.8.0"
 ttrpc = "0.8.2"
 
 [build-dependencies]