Bump protobuf from 3.0.0-alpha.1 to 3.0.0-alpha.8

[dependabot]

Bumps protobuf from 3.0.0-alpha.1 to 3.0.0-alpha.8.

Changelog

Sourced from protobuf's changelog.

[3.0.0-alpha.8] - 2022-02-21

• Lite runtime generation is restored. When lite runtime requested, code is generated without reflection support.
• lite option can be specified when using protoc-gen-rust plugin similarly to how C++ or Java do.

[3.0.0-alpha.7] - 2022-02-20

• Getters are now generated without get_ prefix. get_ prefix also removed from public API functions.
• Reflection API now supports ServiceDescriptor. Which can be used to generate code for gRPC for example.
• Message size computation uses u64 now. It is explicit error now on attempt to serialize a message larger than 2GiB.
• Binary message parsing now switches by tag, not by field name. It is faster.

[3.0.0-alpha.6] - 2022-02-08

• Fixed invalid aliasing and uninitialized memory access
• MessageField now implements Deref and DerefMut
• Slightly more compact generated code
• serde is no longer supported natively. See explanations in the issue.
• Rename ProtobufError to Error and make it opaque type. Rename ProtobufResult to Result.
• Rename ProtobufEnum to Enum and ProtobufEnumOrUnknown to EnumOrUnknown
• gen_mod_rs option is true by default now: code generator now generates mod.rs with modules
• carllerche options renamed to tokio (since bytes crate now lives in tokio org)
• protobuf-parse API cleanup (API used to parse .proto files, not protocol buffers data files)
• Remove protoc crate, most of it is incorprotated into protobuf-parse crate, and the rest is not very useful
• Generated enums for oneof are marked #[non_exhaustive]

[3.0.0-alpha.5] - 2022-02-02

• Dynamic messages work (but not tested enough)

[3.0.0-alpha.4] - 2022-02-02

• Display for message now outputs text format, and Debug for message does standard rust #[derive(Debug)].
• Smaller generated code (common code snippets extracted into the library runtime)
• Improvements in dynamic messages

[3.0.0-alpha.3] - 2022-02-01

• Remove protobuf-codegen-pure and protoc-rust crates. Now all codegen (pure or with protoc is done using protobuf-codegen crate).
• LazyV2 (internal utility for rust-protobuf) now implements Drop.
• Default .proto parser in protobuf-codegen is now pure-rust (not using protoc command)
• Dynamic messages mostly work

[3.0.0-alpha.2] - 2021-11-01

• Use always_output_default_values option to output empty array for repeated fields when serializing to JSON
• Switch error handling to thiserror and anyhow crates

... (truncated)

Commits

• 513b315 Bump version to 3.0.0-alpha.8
• 24280e8 rustfmt
• 9213292 Fix compilation
• aaf2dd9 Protoc crate is dead
• c976903 Mention lite runtime
• 2c6bf42 Fix compilation on nightly
• 9086470 Some docs for Customize struct
• c83c649 Fix compilation on nightly
• b6e8e03 Fix rustdoc
• cb75579 Update CHANGELOG.md
• Additional commits viewable in compare view

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