Add bazel 8 support to pkg_config_repository() (google#1118) (google#…

…1144)

bazel 8 set --incompatible_disallow_empty_glob default to True. For
pkg-confg repository, libexec is likely to be empty, so empty should be
allowed there.

PiperOrigin-RevId: 707430069

src/bazel/pkg_config_repository.bzl

@@ -75,7 +75,7 @@ cc_library(
 """
 
 EXPORTS_FILES_TEMPLATE = """
-exports_files(glob(["libexec/*"]))
+exports_files(glob(["libexec/*"], allow_empty=True))
 """
 
 def _exec_pkg_config(repo_ctx, flags):