segfault in test process glue when llvm_prof missing in rust 1.79

We see this:

```
Coverage runner: Not collecting coverage for failed test.
The following commands failed with status 139
/worker/build/8/root/bazel-out/linux_amd64-fastbuild/bin/build/rules/csdd/test-765406358/unit_test.runfiles/_main/build/rules/csdd/test-765406358/unit_test
thread 'main' panicked at external/rules_rust~/util/collect_coverage/collect_coverage.rs:140:10:
Failed to spawn llvm-profdata process: Os { code: 2, kind: NotFound, message: "No such file or directory" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

With rust 1.79 but not with rust 1.77.

We have neither `llvm_profdata` nor `llvm_cov` set / referenced in our Bazel code.

bazel test output

```
exited with error code -1
Standard Output
Generated test.log (if the file is not UTF-8, then this may be unreadable):
exec ${PAGER:-/usr/bin/less} "$0" || exit 1
Executing tests from //build/rules/csdd:unit_test
-----------------------------------------------------------------------------
running 3 tests
test services::redis::tests::test_redis ... ok
test services::postgres::tests::test_postgres ... ok
test services::pubsub::tests::test_pubsub ... ok
test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 3.25s
external/bazel_tools/tools/test/collect_coverage.sh: line 166: 4054 Segmentation fault "$@"
--
Coverage runner: Not collecting coverage for failed test.
The following commands failed with status 139
/worker/build/8/root/bazel-out/linux_amd64-fastbuild/bin/build/rules/csdd/test-765406358/unit_test.runfiles/_main/build/rules/csdd/test-765406358/unit_test
thread 'main' panicked at external/rules_rust~/util/collect_coverage/collect_coverage.rs:140:10:
Failed to spawn llvm-profdata process: Os { code: 2, kind: NotFound, message: "No such file or directory" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Jun 25, 2024 6:12:09 AM com.google.devtools.coverageoutputgenerator.Main getTracefiles
INFO: No lcov file found.
Jun 25, 2024 6:12:09 AM com.google.devtools.coverageoutputgenerator.Main getGcovInfoFiles
INFO: No gcov info file found.
Jun 25, 2024 6:12:09 AM com.google.devtools.coverageoutputgenerator.Main getGcovJsonInfoFiles
INFO: No gcov json file found.
Jun 25, 2024 6:12:09 AM com.google.devtools.coverageoutputgenerator.Main getProfdataFileOrNull
INFO: No .profdata file found.
Jun 25, 2024 6:12:09 AM com.google.devtools.coverageoutputgenerator.Main runWithArgs
WARNING: There was no coverage found.
Action details (uncached result): http://bb-browser.iap.....dev/blobs/sha256/historical_execute_response/23f538e6964c6cb98c49831a6b060c7bd9b1646639d68d0fcc0a827a628f9339-1193/
```