Protocol Buffers 33.0

What's new in this version:

Bazel:
- Feat: update bazel central registry publish workflow
- Add target_compatible_with parameter to proto_toolchain in Bazel rules
- Bazel: add missing rules_cc loads

Compiler:
- Disable symbol visibility enforcement by default in C++ runtime
- Ship all option dependencies to plugins along with regular ones

C++:
- Avoid calling deprecated arena-enabled constructors in arena.h
- Add a macro to make RepeatedField(Arena*) constructor private in a future release
- Add a macro to make Map(Arena*) constructor private in a future release
- Optimize ReadPackedVarint
- Add a macro to make RepeatedPtrField(Arena*) constructor private in a future release
- Add IsEmpty() function to reflection
- Refactor RuntimeAssertInBounds to remove repeated logic and make Get/Mutable easier to read
- Disable symbol visibility enforcement by default in C++ runtime
- Fix a bug in the main C++ JSON parser/serializer camelcasing of certain non-style-compliant names incorrectly, in a way that would prevent it from interoperating with any other implementation on those fields
- Fail early for messages with more than 65k fields
- Add option to C++ JSON Parser/Serializer to allow customers to affirmatively disable legacy bug-compatibilty behaviors
- Fix mishandling on JSON serialization of Timestamp with invalid negative and too-large nanos value
- Preserve features in type resolver
- Add a DCHECK that ArenaStringPtr::Set(char*, Arena*) is not called with

Java:
- Switch the pre22 warning to use CopyOnWriteArraySet.
- Expose helpers for checking if messages and enums are nested
- Fix a bug calculating the file name in the absense of directories
- Clarify the public APIs of GeneratorNames helpers
- Expose helpers to predict generated class names in java
- Deprecate ClassName methods in favor of new QualifiedClassName ones
- Restore the 3-argument internalBuildGeneratedFileFrom
- Fix large java enums not being honored on lite runtime
- Slightly relax Java Poison Pill on prerelease versions
- Avoid boxing/unboxing varint, fixed32, and fixed64 fields in UnknownFieldSet.Field
- Readd new*List() methods on GeneratedMessageV3
- Add Values.of(Map<String, Value> values)
- Fix handling of optional dependencies in java generator
- Restore ABI compatibility for extension methods which was previously
- Restore Protobuf Java extension modifiers in gencode that were previously removed in 7bff169
- Ship all option dependencies to plugins along with regular ones
- Optimize redaction state calculation
- Add isPlaceholder() accessors to file, message, and enum descriptors
- Improve Java gencode static initialization to avoid unnecessary temporaries again
- Improve Java gencode static initialization to avoid unnecessary temporaries
- Remove protobuf-util usages of guava except annotations
- Restore compatibility of runtime with pre-3.22.x gencode impacted by CVE-2022-3171
- Expose an iterator for GeneratedMessage.ExtendableMessage.extensions

Rust:
- Change Rust prelude to bring in traits as _
- Make message Muts Send
- See also UPB changes below, which may affect Rust.

Python:
- Publish s390x wheels for Python/upb
- Fix a crash that happens during shutdown due to looking up modules in the cache
- Add construction support for repeated Timestamp/Duration/Struct/ListValue
- Fix handling of repeated extension fields in PyProto JSON
- Fixed a parser bug where closed enums are parsed incorrectly for non-repeated extensions
- Fixed mypy errors by setting __slots__ to empty in .pyi files
- Raise warnings for float_precision from python json_format
- Raise warnings when assign bool to int/enum field in Python Proto. This will turn into error in 34.0 release

PHP:
- Fix(php): php errors on repeated field

UPB (Python/PHP/Ruby C-Extension):
- Fixed a parser bug where closed enums are parsed incorrectly for non-repeated extensions.

Other:
- Update token for BCR release to reuse existing BOT_ACCESS_TOKEN used for staleness_refresh.yml and update_php_repo.yml
- Use the 'better' JSON parser on the conformance suite harness
- Add JSON conformance test that a single value provided for a repeated field should parse fail