Remove deprecate action

https://old.reddit.com/r/rust/comments/vyx4oj/actionsrs_organization_became_unmaintained/

Looking at this holistically, I don't fully understand *why* we need an
action here? Seems like we can just use rustup? nowadays github runners
come with rustup pre-installed.

.github/workflows/ci.yaml

@@ -38,7 +38,9 @@ jobs:
         fetch-depth: 20
 
     - name: Install Rust toolchain
-      run: rustup update stable && rustup component add rustfmt rust-src
+      run: |
+        rustup update stable
+        rustup component add rustfmt rust-src
 
     - name: Cache Dependencies
       uses: Swatinem/rust-cache@ce325b60658c1b38465c06cc965b79baf32c1e72
@@ -66,10 +68,9 @@ jobs:
       uses: actions/checkout@v3
 
     - name: Install Rust toolchain
-      run: rustup update stable
-
-    - name: Install Rust targets
-      run: rustup target add ${{ env.targets }} ${{ env.targets_ide }}
+      run: |
+        rustup update stable
+        rustup target add ${{ env.targets }} ${{ env.targets_ide }}
 
     - name: Cache Dependencies
       uses: Swatinem/rust-cache@ce325b60658c1b38465c06cc965b79baf32c1e72

.github/workflows/metrics.yaml

@@ -20,7 +20,9 @@ jobs:
       uses: actions/checkout@v3
 
     - name: Install Rust toolchain
-      run: rustup update stable && rustup component add rustfmt rust-src
+      run: |
+        rustup update stable
+        rustup component add rustfmt rust-src
 
     - name: Collect metrics
       run: cargo xtask metrics

.github/workflows/release.yaml

@@ -55,16 +55,11 @@ jobs:
         with:
           fetch-depth: ${{ env.FETCH_DEPTH }}
 
-      # We need to disable the existing toolchain to avoid updating rust-docs
-      # which takes a long time. The fastest way to do this is to rename the
-      # existing folder, as deleting it takes about as much time as not doing
-      # anything and just updating rust-docs.
-      - name: Rename existing Rust toolchain
-        if: matrix.os == 'windows-latest'
-        run: Rename-Item C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc C:\Users\runneradmin\.rustup\toolchains\stable-x86_64-pc-windows-msvc.old
-
       - name: Install Rust toolchain
-        run: rustup update stable && rustup target add ${{ matrix.target }} && rustup component add rust-src
+        run: |
+          rustup update stable
+          rustup target add ${{ matrix.target }}
+          rustup component add rust-src
 
       - name: Install Node.js
         uses: actions/setup-node@v1