[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/Cargo.lock

@@ -1975,7 +1975,7 @@ name = "codex-utils-cargo-bin"
 version = "0.0.0"
 dependencies = [
  "assert_cmd",
- "path-absolutize",
+ "runfiles",
  "thiserror 2.0.17",
 ]
 
@@ -6592,6 +6592,11 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "runfiles"
+version = "0.1.0"
+source = "git+https://github.com/dzbarsky/rules_rust?rev=b56cbaa8465e74127f1ea216f813cd377295ad81#b56cbaa8465e74127f1ea216f813cd377295ad81"
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.25"