build: Check-in Cargo.lock files and lockdown .net (#384)

Use frozen and locked builds

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

.github/workflows/test-c-cpp.yml

@@ -20,7 +20,8 @@ jobs:
 
       - name: Workaround to ensure that regorus.h is generated
         run: |
-          cargo build -r
+          cargo fetch
+          cargo build -r --frozen
         working-directory: ./bindings/ffi
         
       - name: Test c binding