Revert "Fix CI problems (#127)" and Remove sscache

This reverts commit 12afb13e9b.

.github/workflows/check.yml

@@ -10,10 +10,6 @@ jobs:
   check:
     name:                       Check
     runs-on:                    ubuntu-16.04
-    env:
-      SCCACHE_CACHE_SIZE:       "1G"
-      SCCACHE_IDLE_TIMEOUT:     0    
-      ACTIONS_ALLOW_UNSECURE_COMMANDS: true
     steps:
       - name:                   Checkout sources
         uses:                   actions/checkout@main
@@ -25,32 +21,6 @@ jobs:
           toolchain:            stable
           profile:              minimal
           override:             true
-      - name:                   Cache cargo registry
-        uses:                   actions/cache@v1.1.2
-        with:
-          path:                 ~/.cargo/registry
-          key:                  ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
-      - name:                   Cache cargo index
-        uses:                   actions/cache@v1.1.2
-        with:
-          path:                 ~/.cargo/git
-          key:                  ${{ runner.os }}-cargo-git-${{ hashFiles('**/Cargo.lock') }}
-      - name:                   Cache cargo build
-        uses:                   actions/cache@v1.1.2
-        with:
-          path:                 target
-          key:                  ${{ runner.os }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
-      # Install sccache based on https://github.com/denoland/rusty_v8/blob/master/.github/workflows/ci.yml#L69
-      - name:                   Cache sccache
-        uses:                   actions/cache@v1.1.2
-        with:
-          path:                 "/home/runner/.cache/sccache"
-          key:                  ${{ runner.os }}-sccache-check-${{ hashFiles('**/Cargo.lock') }}
-      - name:                   Install sccache for Linux
-        shell:                  pwsh
-        run:                    pwsh scripts/actions/install-sccache.ps1 ${{ runner.os}}
-      - name:                   Sccache statistics
-        run:                    sccache --show-stats
       - name:                   Run cargo check 1/3
         uses:                   actions-rs/cargo@v1
         with:
@@ -78,10 +48,3 @@ jobs:
           args:                 --locked --all --benches --verbose
       - name:                   Run validate chainspecs
         run:                    ./scripts/actions/validate-chainspecs.sh
-      - name:                   Stop sccache
-        if:                     always()
-        run:                    sccache --stop-server
-        continue-on-error:      true
-      - name:                   Prepare build directory for cache
-        shell: bash
-        run:                    bash scripts/actions/clean-target.sh