Upgrade the Rust toolchain to 1.99.1 (#61205)

## What changed

- Update the workspace, Bazel toolchain and lockfile, CI and release workflows, and Windows setup script from Rust `1.95.0` to `1.99.1`.
- Adapt Rust code to the updated toolchain and Clippy lints, including `try_update` for atomics, `as_chunks` for fixed-size slices, and targeted allowances for generated tonic services.
- Refresh the halfwidth sound mark rendering snapshot to use literal characters in debug output.

GitOrigin-RevId: 5852029f687436dc814c2bca68141ee1f4a67d49

.github/workflows/v8-canary.yml

@@ -179,9 +179,9 @@ jobs:
           python-version: "3.12"
 
       - name: Set up Rust toolchain for Cargo smoke
-        uses: dtolnay/rust-toolchain@e081816240890017053eacbb1bdf337761dc5582 # 1.95.0
+        uses: dtolnay/rust-toolchain@d124f86f28ff42855784ff3319f48ac182c248f8 # 1.99.1
         with:
-          toolchain: "1.95.0"
+          toolchain: "1.99.1"
           targets: ${{ matrix.target }}
 
       - name: Build Bazel V8 release pair
@@ -347,9 +347,9 @@ jobs:
           architecture: x64
 
       - name: Set up Codex Rust toolchain for Cargo smoke
-        uses: dtolnay/rust-toolchain@e081816240890017053eacbb1bdf337761dc5582 # 1.95.0
+        uses: dtolnay/rust-toolchain@d124f86f28ff42855784ff3319f48ac182c248f8 # 1.99.1
         with:
-          toolchain: "1.95.0"
+          toolchain: "1.99.1"
           targets: ${{ matrix.target }}
 
       - name: Install rusty_v8 Rust toolchain
@@ -439,7 +439,7 @@ jobs:
             cd codex-rs
             RUSTY_V8_ARCHIVE="${GITHUB_WORKSPACE}/${archive}" \
             RUSTY_V8_SRC_BINDING_PATH="${GITHUB_WORKSPACE}/${binding}" \
-            cargo +1.95.0 test -p codex-v8-poc --target "${TARGET}" --features sandbox --no-run
+            cargo +1.99.1 test -p codex-v8-poc --target "${TARGET}" --features sandbox --no-run
           )
 
       - name: Upload staged artifacts