rules_cc runfiles library does not provide `BAZEL_CURRENT_REPOSITORY`

### Description of the problem / feature request:

The runfiles library has been deprecated in bazel-tools and now points to the library in rules_cc, but the instructions ported over refer to [BAZEL_CURRENT_REPOSITORY](https://github.com/bazelbuild/rules_cc/blob/5be90a4e04e64df0e9d26382e1006d3df21aaa91/cc/runfiles/runfiles.h#L37), which is not present in the rules_cc runfiles library.

### Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

I made a branch off something I was working on. You should be able to run `touch data/inputs/01.txt && bazel build //src/day/01` using //https://github.com/flurie/aoc-2024/tree/demo-rules-cc-runfiles if you install the prereqs (nix and devenv) and it should work on macOS and Linux.

### What operating system are you running Bazel on?

macOS 14.5

### What's the output of `bazel info release`?

`release 7.4.1- (@non-git)`

### If `bazel info release` returns "development version" or "(@non-git)", tell us how you built Bazel.

It is built from nixpkgs 24.11.

### What version of rules_cc do you use? Can you paste the workspace rule used to fetch rules_cc? What other relevant dependencies does your project have?

```
http_archive(
name = "rules_cc",
urls = ["https://github.com/bazelbuild/rules_cc/releases/download/0.0.17/rules_cc-0.0.17.tar.gz"],
sha256 = "abc605dd850f813bb37004b77db20106a19311a96b2da1c92b789da529d28fe1",
strip_prefix = "rules_cc-0.0.17",
)
```

### What Bazel options do you use to trigger the issue? What C++ toolchain do you use?

.bazelrc:
```
build --host_platform=@rules_nixpkgs_core//platforms:host
build --crosstool_top=@nixpkgs_config_cc//:toolchain
```

for completeness, the output when the repro command is run with `--announce_rc`:
```
INFO: Reading 'startup' options from /nix/store/zsyc077bgm4g3xq3h0a2qfzw4g4jzjfi-bazel-rc: --server_javabase=/nix/store/dd8l9acgfnax38j7wvz0lh96c2vkxyg3-zulu-ca-jdk-21.0.4
INFO: Options provided by the client:
Inherited 'common' options: --isatty=1 --terminal_columns=104
INFO: Reading rc options for 'run' from /nix/store/zsyc077bgm4g3xq3h0a2qfzw4g4jzjfi-bazel-rc:
Inherited 'build' options: --extra_toolchains=@bazel_tools//tools/jdk:all --tool_java_runtime_version=local_jdk --java_runtime_version=local_jdk
INFO: Reading rc options for 'run' from /Users/flurie/Repos/github.com/flurie/aoc-2024/.bazelrc:
Inherited 'build' options: --host_platform=@rules_nixpkgs_core//platforms:host --crosstool_top=@nixpkgs_config_cc//:toolchain
```

toolchain:
```
nixpkgs_git_repository(
name = "nixpkgs",
revision = "release-24.11",
)

nixpkgs_cc_configure(
name = "nixpkgs_config_cc",
repository = "@nixpkgs",
)
```

### Have you found anything relevant by searching the web?

No

### Any other information, logs, or outputs that you want to share?

No