pbtk: abrogate system_python cc headers with rules_python cc headers

#test-continuous

PiperOrigin-RevId: 782898514

Author: honglooker

python/build_targets.bzl

@@ -98,7 +98,7 @@ def build_targets(name):
         ],
         deps = select({
             "//conditions:default": [],
-            ":use_fast_cpp_protos": ["@system_python//:python_headers"],
+            ":use_fast_cpp_protos": ["@rules_python//python/cc:current_py_cc_headers"],
         }),
     )
 
@@ -154,7 +154,7 @@ def build_targets(name):
             "@abseil-cpp//absl/strings",
         ] + select({
             "//conditions:default": [],
-            ":use_fast_cpp_protos": ["@system_python//:python_headers"],
+            ":use_fast_cpp_protos": ["@rules_python//python/cc:current_py_cc_headers"],
         }),
     )
 
@@ -459,7 +459,7 @@ def build_targets(name):
             "//src/google/protobuf/io",
             "@abseil-cpp//absl/log:absl_check",
             "@abseil-cpp//absl/status",
-            "@system_python//:python_headers",
+            "@rules_python//python/cc:current_py_cc_headers",
         ],
     )