Unbreak after 0.71.0 release of rules_rust

Summary:

The `0.71.0` release of `rules_rust` broke `gazelle_rust` by removing the
deprecated `@rules_rust//crate_universe:extension.bzl` target.

This commit updates `use_extension()` within MODULE.bazel to use the modern
`extensions.bzl` target.

This commit also takes the opportunity to update several bzlmod dependencies,
which required resolving several clippy errors in
`gazelle_rust_parser/src/lib.rs` that newly appeared after updating
`rules_rust` to `0.71.0`

Notes:

- Updating `rules_rust` to `0.71.0` instead of `0.71.1` due to incompatibility
  between `rules_proto` and `rules_rust`
  - protocolbuffers/protobuf#28224


These changes are NOT AI generated, and I offer it to the gazelle_rust project
under the terms of the APACHE license.

- [fix] Fix use_extension() target for crate_universe in MODULE.bazel
- [style] Fix clippy issues in `gazelle_rust_parser/src/lib.rs`
- [build] Use golang version from `go.mod`
- [build] Ignore cargo `/target` directories
- [dep] Update bazel from `8.4.2` to `8.7.0`
- [dep] Update `rules_shell` from `0.6.1` to `0.8.1`
- [dep] Update `rules_go` from `0.59.0` to `0.61.1`
- [dep] Update `gazelle` from `0.47.0` to `0.51.3`
- [dep] Update `rules_rust` from `0.67.0` to `0.71.0`
- [dep] Update `rules_rust_prost` from `0.67.0` to `0.71.0`
- [dep] Update cargo packages in both root and `example` directories
- [dep] Clean up `go.mod` with `bazel run @rules_go//go -- mod tidy -e`

Test Plan:

```bash
$> bazel build --config check //...
INFO: Invocation ID: 36981488-710f-4ce8-8d3e-da03fecc2097
INFO: Analyzed 60 targets (0 packages loaded, 0 targets configured).
INFO: Found 60 targets...
INFO: Elapsed time: 0.184s, Critical Path: 0.00s
INFO: 1 process: 108 action cache hit, 1 internal.
INFO: Build completed successfully, 1 total action
$> bazel test //...
[ ... SNIP ... ]
Executed 41 out of 41 tests: 41 tests pass.
$> cd example
$> bazel build //...
INFO: Invocation ID: e7b360fd-7d64-4ad4-84fd-4735db416990
INFO: Analyzed 5 targets (79 packages loaded, 4020 targets configured).
INFO: Found 5 targets...
INFO: Elapsed time: 11.750s, Critical Path: 9.23s
INFO: 130 processes: 1360 action cache hit, 25 internal, 105 processwrapper-sandbox.
INFO: Build completed successfully, 130 total actions
$> bazel test //...
[ ... SNIP ... ]
Executed 2 out of 2 tests: 2 tests pass.
$>
```

Author: ckwalsh

.bazelversion

@@ -1 +1 @@
-8.4.2
+8.7.0

.gitignore

@@ -2,4 +2,5 @@
 /build
 /macro/target
 /gazelle_rust_parser/target
+/target
 rust-project.json