Revert "[ruby/yarp] rust: Initial yarp-sys"

This reverts commit e6e23b92e3019e27471c9bf7a97db5f95e7a9a29.

It seems like it wasn't added for ruby/ruby.

We could fix tool/sync_default_gems.rb to deal with this, but we have a
pull request that changes that part now, so let me only revert this for
now and revisit this after merging that pull request.

.github/workflows/rust-bindings.yml

@@ -1,101 +0,0 @@
----
-name: Rust Bindings
-
-on:
-  push:
-    paths:
-      - ".github/workflows/rust-bindings.yml"
-      - "include/"
-      - "src/"
-      - "rust/"
-      - "*akefile*"
-    branches:
-      - main
-  pull_request:
-
-env:
-  RUSTFLAGS: "-D warnings"
-
-jobs:
-  cargo-test:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: head
-          bundler-cache: true
-      - uses: actions/cache@v3
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-${{ hashFiles('Cargo.toml') }}
-            ${{ runner.os }}-cargo
-      - name: rake compile
-        run: bundle exec rake compile
-      - name: cargo test
-        working-directory: rust/yarp-sys
-        run: cargo test
-
-  cargo-clippy:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: head
-          bundler-cache: true
-      - uses: actions/cache@v3
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-${{ hashFiles('Cargo.toml') }}
-            ${{ runner.os }}-cargo
-      - name: rake compile
-        run: bundle exec rake compile
-      - name: cargo clippy
-        working-directory: rust/yarp-sys
-        run: cargo clippy --tests -- -W "clippy::pedantic"
-
-  sanitizer-test:
-    name: Test with -Zsanitizer=${{ matrix.sanitizer }}
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        sanitizer: [address, leak]
-    steps:
-      - uses: actions/checkout@v3
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: head
-          bundler-cache: true
-      - name: rake compile
-        run: bundle exec rake compile
-      - uses: dtolnay/rust-toolchain@nightly
-        with:
-          target: "x86_64-unknown-linux-gnu"
-          components: "rust-src"
-      - name: Test with sanitizer
-        env:
-          RUSTFLAGS: -Zsanitizer=${{ matrix.sanitizer }}
-          RUSTDOCFLAGS: -Zsanitizer=${{ matrix.sanitizer }}
-          # only needed by asan
-          ASAN_OPTIONS: detect_stack_use_after_return=1
-          # Asan's leak detection occasionally complains
-          # about some small leaks if backtraces are captured,
-          # so ensure they're not
-          RUST_BACKTRACE: 0
-        working-directory: rust/yarp-sys
-        run: cargo test -Zbuild-std --verbose --target=x86_64-unknown-linux-gnu