[bazel] Improve runfiles handling (#10098)

we can't use runfiles directory on Windows due to path lengths, so swap
to manifest strategy. Parsing the manifest is a bit complex and the
format is changing in Bazel upstream, so pull in the official Rust
library (via a small hack to make it importable...) and cleanup all the
associated logic to work cleanly in both bazel and cargo without extra
confusion

codex-rs/utils/cargo-bin/BUILD.bazel

@@ -3,4 +3,10 @@ load("//:defs.bzl", "codex_rust_crate")
 codex_rust_crate(
     name = "cargo-bin",
     crate_name = "codex_utils_cargo_bin",
+    compile_data = ["repo_root.marker"],
+    lib_data_extra = ["repo_root.marker"],
+    test_data_extra = ["repo_root.marker"],
+    rustc_env = {
+        "CODEX_REPO_ROOT_MARKER": "$(rlocationpath :repo_root.marker)",
+    },
 )