Fix bazel formatting (#3583)

Fixes the following error:

```
rust/toolchain.bzl:867: unsorted-dict-items: Dictionary items are out of their lexicographical order. (https://github.com/bazelbuild/buildtools/blob/main/WARNINGS.md#unsorted-dict-items)
```

Author: nmattia

rust/toolchain.bzl

@@ -859,16 +859,16 @@ rust_toolchain = rule(
             allow_single_file = True,
             cfg = "exec",
         ),
-        "llvm_profdata": attr.label(
-            doc = "The location of the `llvm-profdata` binary. Can be a direct source or a filegroup containing one item. If `llvm_cov` is None, this can be None as well and rust code is not instrumented for coverage.",
-            allow_single_file = True,
-            cfg = "exec",
-        ),
         "llvm_lib": attr.label(
             doc = "The location of the `libLLVM` shared object files. If `llvm_cov` is None, this can be None as well and rust code is not instrumented for coverage.",
             allow_files = True,
             cfg = "exec",
         ),
+        "llvm_profdata": attr.label(
+            doc = "The location of the `llvm-profdata` binary. Can be a direct source or a filegroup containing one item. If `llvm_cov` is None, this can be None as well and rust code is not instrumented for coverage.",
+            allow_single_file = True,
+            cfg = "exec",
+        ),
         "llvm_tools": attr.label(
             doc = "LLVM tools that are shipped with the Rust toolchain.",
             allow_files = True,