Remove all autotools usage (#10132)

* Bazelfying conformance tests

Adding infrastructure to "Bazelify" languages other than Java and C++

* Delete benchmarks for languages supported by other repositories

* Bazelfying benchmark tests

* Bazelfying python

Use upb's system python rule instead of branching tensorflow

* Bazelfying Ruby

* Bazelfying C#

* Bazelfying Objective-c

* Bazelfying Kokoro mac builds

* Bazelfying Kokoro linux builds

* Deleting all deprecated files from autotools cleanup

This boils down to Makefile.am and tests.sh and all of their remaining references

* Cleanup after PR reorganizing

- Enable 32 bit tests
- Move conformance tests back
- Use select statements to select alternate runtimes
- Add internal prefixes to proto library macros

* Updating READMEs to use bazel instead of autotools.

* Bazelfying Kokoro release builds

* First round of review fixes

* Second round of review fixes

* Third round of review fixes

* Filtering out conformance tests from Bazel on Windows (b/241484899)

* Add version metadata that was previously scraped from configure.ac

* fixing typo from previous fix

* Adding ruby version tests

* Bumping pinned upb version, and adding tests to python CI
diff --git a/WORKSPACE b/WORKSPACE
index d01122a..ebe5331 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -30,11 +30,6 @@
 load("//:protobuf_deps.bzl", "PROTOBUF_MAVEN_ARTIFACTS", "protobuf_deps")
 protobuf_deps()
 
-bind(
-    name = "python_headers",
-    actual = "//util/python:python_headers",
-)
-
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
@@ -69,3 +64,11 @@
 
 load("@upb//bazel:workspace_deps.bzl", "upb_deps")
 upb_deps()
+
+load("@upb//bazel:system_python.bzl", "system_python")
+system_python(name = "local_config_python")
+
+bind(
+    name = "python_headers",
+    actual = "@local_config_python//:python_headers",
+)