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

docs/cpp_build_systems.md

diff --git a/docs/cpp_build_systems.md b/docs/cpp_build_systems.md
index 812ddef..e093f9a 100644
--- a/docs/cpp_build_systems.md
+++ b/docs/cpp_build_systems.md
@@ -25,9 +25,9 @@
   was designed in large part to support exactly this type of rich,
   multi-language build.
 
-Currently, C++ Protobuf can be built with Bazel, Autotools, and CMake. Each of
-these build systems has different semantics and structure, but share in common
-the list of files needed to build the runtime and compiler.
+Currently, C++ Protobuf can be built with Bazel and CMake. Each of these build
+systems has different semantics and structure, but share in common the list of
+files needed to build the runtime and compiler.
 
 ## Design
 
@@ -74,7 +74,7 @@
 libraries into a single, monolithic library.
 
 For the Protobuf project, these "distribution libraries" are intended to match
-the granularity of the Autotools- and CMake-based builds. Since the Bazel-built
+the granularity of the CMake-based builds. Since the Bazel-built
 distribution library covers the rules with the source files needed by other
 builds, the `cc_dist_library` rule invokes the `cc_file_list_aspect` on its
 input libraries. The result is that a `cc_dist_library` rule not only produces
@@ -163,8 +163,7 @@
 ### File list generation
 
 Lists of input files are generated by Bazel in a format that can be imported to
-other build systems. Currently, Automake- and CMake-style files can be
-generated.
+other build systems. Currently only CMake-style files can be generated.
 
 The lists of files are derived from Bazel build targets. The sources can be:
 *   `cc_dist_library` rules (as described above)
@@ -263,11 +262,6 @@
 add_library(distlib ${distlib_srcs} ${buff_srcs})
 ```
 
-In addition to `gen_cmake_file_lists`, there is also a `gen_automake_file_lists`
-rule. These rules actually share most of the same implementation, but define
-different file headers and different Starlark "fragment generator" functions
-which format the generated list variables.
-
 ### Protobuf usage
 
 The main C++ runtimes (lite and full) and the Protobuf compiler use their

docs/implementing_proto3_presence.md

diff --git a/docs/implementing_proto3_presence.md b/docs/implementing_proto3_presence.md
index 7c3e213..4abfbd5 100644
--- a/docs/implementing_proto3_presence.md
+++ b/docs/implementing_proto3_presence.md
@@ -131,11 +131,11 @@
 
 ```
 # One option:
-$ ./src/protoc test.proto --cpp_out=. --experimental_allow_proto3_optional
+$ protoc test.proto --cpp_out=. --experimental_allow_proto3_optional
 
 # Another option:
 $ cp test.proto test_proto3_optional.proto
-$ ./src/protoc test_proto3_optional.proto --cpp_out=.
+$ protoc test_proto3_optional.proto --cpp_out=.
 $
 ```
 
@@ -152,7 +152,7 @@
 run into a different error:
 
 ```
-$ ./src/protoc test_proto3_optional.proto --my_codegen_out=.
+$ protoc test_proto3_optional.proto --my_codegen_out=.
 test_proto3_optional.proto: is a proto3 file that contains optional fields, but
 code generator --my_codegen_out hasn't been updated to support optional fields in
 proto3. Please ask the owner of this code generator to support proto3 optional.
@@ -201,7 +201,7 @@
 generator to generate a file containing proto3 optional fields:
 
 ```
-$ ./src/protoc test_proto3_optional.proto --my_codegen_out=.
+$ protoc test_proto3_optional.proto --my_codegen_out=.
 ```
 
 ### Updating Your Code Generator