xls_cc_ir rule in xls/tools/testdata makes XLS core wildcard build all of xlscc

[cdleary]

Describe the bug

$ bazel cquery 'somepath((((//xls/... except //xls/contrib/...) except //xls/dev_tools/...) except //xls/tools:proto2bin), //xls/contrib/xlscc/...)' 
//xls/tools/testdata:eval_proc_main_test_test_memory_cc_ir (3e86c6b)
//xls/contrib/xlscc:xlscc (42dce80)
//xls/contrib/xlscc:metadata_output_cc_proto (42dce80)

Expected behavior
Build of that wildcard should not require xlscc to build.

Additional context
Perhaps we should consider a bazel cquery test to help indicate when a dependency crops up.

[cdleary]

This seems to be causing the latest OSS build breakage (via clang dep) when using standard wildcards:

ERROR: /home/cdleary/.cache/bazel/_bazel_cdleary/e3482f322694a8d1a6845914a1a3d787/external/llvm-project/clang/BUILD.bazel:676:11: Compiling clang/lib/Basic/Warnings.cpp [for tool] failed: (Exit 1): cc_wrapper.sh failed: error executing CppCompile command (from target @@llvm-project//clang:basic) external/llvm_toolchain/bin/cc_wrapper.sh -U_FORTIFY_SOURCE '--target=x86_64-unknown-linux-gnu' -U_FORTIFY_SOURCE -fstack-protector -fno-omit-frame-pointer -fcolor-diagnostics -Wall -Wthread-safety ... (remaining 150 arguments skipped)

Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
In file included from external/llvm-project/clang/lib/Basic/Warnings.cpp:24:
In file included from external/llvm-project/clang/include/clang/Basic/AllDiagnostics.h:17:
external/llvm-project/clang/include/clang/Basic/DiagnosticAST.h:34:10: fatal error: 'clang/Basic/DiagnosticASTEnums.inc' file not found
   34 | #include "clang/Basic/DiagnosticASTEnums.inc"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
INFO: Elapsed time: 179.077s, Critical Path: 74.31s
INFO: 7350 processes: 67 disk cache hit, 1520 internal, 5763 processwrapper-sandbox.
ERROR: Build did NOT complete successfully