Try to find the best parallelisation

This reverts commit a0e923b70b.

.github/workflows/build_and_test.yml

@@ -122,10 +122,12 @@ jobs:
 
   check-codestyle-rust:
     needs: [ check-permissions, build-build-tools-image ]
+    # There's no reason to expect clippy or code formatting to be different on different platforms,
+    # so it's enough to run these on x64 only.
     strategy:
       matrix:
         arch: [ x64, arm64 ]
-    runs-on: ${{ fromJson(format('["self-hosted", "{0}"]', matrix.arch == 'arm64' && 'small-arm64' || 'small')) }}
+    runs-on: ${{ fromJson(format('["self-hosted", "{0}"]', matrix.arch == 'arm64' && 'large-arm64' || 'large')) }}
 
     container:
       image: ${{ needs.build-build-tools-image.outputs.image }}
@@ -166,15 +168,25 @@ jobs:
             exit 1
           fi
           echo "CLIPPY_COMMON_ARGS=${CLIPPY_COMMON_ARGS}" >> $GITHUB_ENV
+
       - name: Run cargo clippy (debug)
-        run: cargo hack --feature-powerset clippy $CLIPPY_COMMON_ARGS
-      - name: Run cargo clippy (release)
-        run: cargo hack --feature-powerset clippy --release $CLIPPY_COMMON_ARGS
+        run: |
+          parallel --jobs 8 "cargo hack --feature-powerset --partition {}/8 clippy --target-dir target/partition-{} $CLIPPY_COMMON_ARGS" ::: 1 2 3 4 5 6 7 8
+
+      # instead of running the full release build, running debug build again,
+      # but with disabled `debug-assertions` to excersice release code paths
+      - name: Run cargo clippy (debug, with debug-assertions=false)
+        run: |
+          for N in 4 8 10 12 14 16 18 20; do
+            echo "Running clippy with debug-assertions=false for partition ${N}"
+            time parallel --jobs ${N} "cargo hack --feature-powerset --partition {}/${N} clippy --target-dir target/partition-{} $CLIPPY_COMMON_ARGS -C debug-assertions=off" ::: $(seq -s " " 1 ${N})
+            rm -rf target/partition-*
+          done
 
       - name: Check documentation generation
         run: cargo doc --workspace --no-deps --document-private-items
         env:
-            RUSTDOCFLAGS: "-Dwarnings -Arustdoc::private_intra_doc_links"
+          RUSTDOCFLAGS: "-Dwarnings -Arustdoc::private_intra_doc_links"
 
       # Use `${{ !cancelled() }}` to run quck tests after the longer clippy run
       - name: Check formatting