Bump bumpalo from 3.8.0 to 3.12.0 (#6599)

Bumps [bumpalo](https://github.com/fitzgen/bumpalo) from 3.8.0 to 3.12.0.
- [Release notes](https://github.com/fitzgen/bumpalo/releases)
- [Changelog](https://github.com/fitzgen/bumpalo/blob/main/CHANGELOG.md)
- [Commits](https://github.com/fitzgen/bumpalo/compare/3.8.0...3.12.0)

---
updated-dependencies:
- dependency-name: bumpalo
  dependency-type: indirect
...

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

polkadot/Cargo.lock

@@ -667,9 +667,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.8.0"
+version = "3.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f1e260c3a9040a7c19a12468758f4c16f31a81a1fe087482be9570ec864bb6c"
+checksum = "0d261e256854913907f67ed06efbc3338dfe6179796deefc1ff763fc1aee5535"
 
 [[package]]
 name = "byte-slice-cast"