ci: temporarily remove mcs-export from proof-deploy

This removes the mcs-export matrix job from the proof-deploy workflow,
as the first step towards solving #497. This should unblock
verification manifest deployments.

The mcs-export job was added to the proof-deploy workflow to perform
SimplExportAndRefine for binary verification targets. It took a short
cut, using the master branch of l4v to perform SimplExportAndRefine for
MCS configurations. This no longer works, because MCS seL4 C code now
contains C parser annotations that use symbols only available in the rt
branch of l4v.

We intend to add an equivalent job that uses the rt branch, but are
still working out the best way to do that.

.github/workflows/proof-deploy.yml

@@ -59,44 +59,10 @@ jobs:
         name: logs-${{ matrix.arch }}
         path: logs.tar.xz
 
-  mcs-export:
-    name: MCS
-    needs: code
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        arch: [ARM, RISCV64]
-    # test only most recent push:
-    concurrency: l4v-regression-${{ github.ref }}-${{ strategy.job-index }}-mcs
-    steps:
-    - name: SimplExport
-      uses: seL4/ci-actions/aws-proofs@master
-      with:
-        L4V_ARCH: ${{ matrix.arch }}
-        L4V_FEATURES: MCS
-        xml: ${{ needs.code.outputs.xml }}
-        session: SimplExportAndRefine
-      env:
-        AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-        AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-        AWS_SSH: ${{ secrets.AWS_SSH }}
-    - name: Upload C graph-lang
-      uses: actions/upload-artifact@v3
-      with:
-        name: c-graph-lang
-        path: artifacts/simpl-export
-        if-no-files-found: ignore
-    - name: Upload logs
-      uses: actions/upload-artifact@v3
-      with:
-        name: logs-${{ matrix.arch }}-MCS
-        path: logs.tar.xz
-
   deploy:
     name: Deploy manifest
     runs-on: ubuntu-latest
-    needs: [code, proofs, mcs-export]
+    needs: [code, proofs]
     steps:
     - uses: seL4/ci-actions/l4v-deploy@master
       with:
@@ -107,7 +73,7 @@ jobs:
   binary-verification:
     name: Trigger binary verification
     runs-on: ubuntu-latest
-    needs: [code, proofs, mcs-export]
+    needs: [code, proofs]
     steps:
     # download-artifact doesn't have an option to ignore missing artifacts,
     # so we download them all to test if c-graph-lang exists.