chore: update mpl submodule name gha (#675)

Author: josecorella

.github/workflows/dafny_interop_test_net.yml

@@ -55,7 +55,7 @@ jobs:
           dafny-version: ${{ inputs.mpl-dafny }}
 
       - name: Update MPL submodule
-        working-directory: submodules/MaterialProviders
+        working-directory: mpl
         run: |
           git fetch
           git checkout ${{inputs.mpl-commit}}

.github/workflows/dafny_interop_test_vector_net.yml

@@ -65,7 +65,7 @@ jobs:
           dafny-version: ${{ inputs.mpl-dafny }}
 
       - name: Update MPL submodule
-        working-directory: submodules/MaterialProviders
+        working-directory: mpl
         run: |
           git fetch
           git checkout ${{inputs.mpl-commit}}
@@ -175,7 +175,7 @@ jobs:
           dafny-version: ${{ inputs.mpl-dafny }}
 
       - name: Update MPL submodule
-        working-directory: submodules/MaterialProviders
+        working-directory: mpl
         run: |
           git fetch
           git checkout ${{inputs.mpl-commit}}
@@ -305,4 +305,4 @@ jobs:
         run: |
           NET_41_VECTOR_PATH=net41/vectors
           cd $NET_41_VECTOR_PATH
-          npx -y @aws-crypto/integration-node decrypt -v net41.zip -c cpu -f 100
+          npx -y @aws-crypto/integration-node decrypt -v net41.zip -c cpu -f 100