[8.3.0] Move Python runfiles library out of Bazel (#26021)

The Python runfiles libraries in @bazel_tools, which isn't fully
functional with Bzlmod, now aliases to `@rules_python//python/runfiles.

This requires skipping load visibility checks for resolved WORKSPACE
files, which are going away anyway.

Partial cherry-pick of b8b91e4

Fixes #26020

Author: fmeum

src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java

@@ -360,7 +360,7 @@ public SkyValue compute(SkyKey skyKey, Environment env)
               keys.build(),
               starlarkSemantics,
               bzlLoadFunctionForInlining,
-              /* checkVisibility= */ true);
+              /* checkVisibility= */ !useWorkspaceResolvedFile);
     } catch (NoSuchPackageException e) {
       throw new WorkspaceFileFunctionException(e, Transience.PERSISTENT);
     }

tools/python/gen_runfiles_constants.bzl

@@ -1,6 +1,3 @@
-load("@rules_python//python:defs.bzl", "py_library", "py_test")
-load("//tools/python:gen_runfiles_constants.bzl", "gen_runfiles_constants")
-
 package(default_visibility = ["//visibility:private"])
 
 filegroup(
@@ -17,23 +14,3 @@ filegroup(
     ],
     visibility = ["//tools/python:__pkg__"],
 )
-
-py_library(
-    name = "runfiles",
-    testonly = 1,
-    srcs = [
-        "runfiles.py",
-        ":_runfiles_constants",
-    ],
-)
-
-gen_runfiles_constants(
-    name = "_runfiles_constants",
-)
-
-py_test(
-    name = "runfiles_test",
-    srcs = ["runfiles_test.py"],
-    visibility = ["//visibility:public"],
-    deps = [":runfiles"],
-)

tools/python/runfiles/BUILD

@@ -1,15 +1,12 @@
-load("//tools/python:gen_runfiles_constants.bzl", "gen_runfiles_constants")
 load("@rules_python//python:defs.bzl", "py_library")
 
 py_library(
     name = "runfiles",
     srcs = [
         "runfiles.py",
-        ":_runfiles_constants",
     ],
     visibility = ["//visibility:public"],
-)
-
-gen_runfiles_constants(
-    name = "_runfiles_constants",
+    deps = [
+        "@rules_python//python/runfiles",
+    ],
 )