Remove sccache to reduce github actions cache churn (#5641)

# Description of Changes

Removing `sccache` from CI workflows since it's churning the github
actions cache. This is causing us to evict the much higher value
`rust-cache` entries quite frequently.

This is part of the work to break up
#5612 into smaller
reviewable chunks.

# API and ABI breaking changes

None

# Expected complexity level and risk

1

# Testing

N/A

Author: joshua-spacetime

.github/actions/keynote-bench-setup/action.yml

@@ -19,15 +19,6 @@ runs:
       shell: bash
       run: rustup default $(rustup show active-toolchain | cut -d' ' -f1)
 
-    - name: Set up sccache
-      uses: mozilla-actions/sccache-action@v0.0.10
-
-    - name: Enable sccache
-      shell: bash
-      run: |
-        echo "SCCACHE_GHA_ENABLED=true" >>"$GITHUB_ENV"
-        echo "RUSTC_WRAPPER=sccache" >>"$GITHUB_ENV"
-
     - name: Cache Rust dependencies
       uses: Swatinem/rust-cache@v2
       with:

.github/workflows/ci.yml

@@ -110,15 +110,6 @@ jobs:
       - name: Set default rust toolchain
         run: rustup default $(rustup show active-toolchain | cut -d' ' -f1)
 
-      - name: Set up sccache
-        uses: mozilla-actions/sccache-action@v0.0.10
-
-      - name: Enable sccache
-        shell: bash
-        run: |
-          echo "SCCACHE_GHA_ENABLED=true" >>"$GITHUB_ENV"
-          echo "RUSTC_WRAPPER=sccache" >>"$GITHUB_ENV"
-
       - name: Cache Rust dependencies
         uses: Swatinem/rust-cache@v2
         with:
@@ -451,14 +442,6 @@ jobs:
       - name: Set default rust toolchain
         run: rustup default $(rustup show active-toolchain | cut -d' ' -f1)
 
-      - name: Set up sccache
-        uses: mozilla-actions/sccache-action@v0.0.10
-
-      - name: Enable sccache
-        run: |
-          echo "SCCACHE_GHA_ENABLED=true" >>"$GITHUB_ENV"
-          echo "RUSTC_WRAPPER=sccache" >>"$GITHUB_ENV"
-
       - name: Cache Rust dependencies
         uses: Swatinem/rust-cache@v2
         with: