remove extra bazel 6 code

Author: aignas

python/private/py_package.bzl

@@ -41,13 +41,8 @@ def _py_package_impl(ctx):
         py_info.merge_target(dep)
     py_info = py_info.build()
     inputs.add(py_info.transitive_sources)
-
-    # Remove conditional once Bazel 6 support dropped.
-    if hasattr(py_info, "transitive_pyc_files"):
-        inputs.add(py_info.transitive_pyc_files)
-
-    if hasattr(py_info, "transitive_pyi_files"):
-        inputs.add(py_info.transitive_pyi_files)
+    inputs.add(py_info.transitive_pyc_files)
+    inputs.add(py_info.transitive_pyi_files)
 
     inputs = inputs.build()
 

python/private/py_runtime_rule.bzl

@@ -384,11 +384,7 @@ The {obj}`PyRuntimeInfo.zip_main_template` field.
 )
 
 def _is_singleton_depset(files):
-    # Bazel 6 doesn't have this helper to optimize detecting singleton depsets.
-    if _py_builtins:
-        return _py_builtins.is_singleton_depset(files)
-    else:
-        return len(files.to_list()) == 1
+    return _py_builtins.is_singleton_depset(files)
 
 def _interpreter_version_info_from_version_str(version_str):
     parts = version_str.split(".")

python/private/python_register_toolchains.bzl

@@ -97,21 +97,6 @@ def python_register_toolchains(
 
     toolchain_repo_name = "{name}_toolchains".format(name = name)
 
-    # When using unreleased Bazel versions, the version is an empty string
-    if native.bazel_version:
-        bazel_major = int(native.bazel_version.split(".")[0])
-        if bazel_major < 6:
-            if register_coverage_tool:
-                # buildifier: disable=print
-                print((
-                    "WARNING: ignoring register_coverage_tool=True when " +
-                    "registering @{name}: Bazel 6+ required, got {version}"
-                ).format(
-                    name = name,
-                    version = native.bazel_version,
-                ))
-            register_coverage_tool = False
-
     # list[str] of the platform names that were used
     loaded_platforms = []