github-ci: cache npcap binary download

.github/workflows/builds.yml

@@ -2809,6 +2809,11 @@ jobs:
         with:
           path: ~/.cargo/registry
           key: cargo-registry
+      - name: Cache npcap
+        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          path: /npcap-bin
+          key: npcap-bin-100
       - uses: msys2/setup-msys2@v2
         with:
           msystem: MINGW64
@@ -2827,10 +2832,12 @@ jobs:
       - run: tar xf prep/suricata-update.tar.gz
       - name: Npcap DLL
         run: |
-          curl -sL -O https://nmap.org/npcap/dist/npcap-1.00.exe
-          7z -y x -o/npcap-bin npcap-1.00.exe
-          # hack: place dlls in cwd
-          cp /npcap-bin/*.dll .
+          if ! test -e /npcap-bin; then
+              curl -sL -O https://nmap.org/npcap/dist/npcap-1.00.exe
+              7z -y x -o/npcap-bin npcap-1.00.exe
+          fi
+      - name: Place NPcap dll's in curent directory 
+        run: cp /npcap-bin/*.dll .
       - name: Npcap SDK
         run: |
           curl -sL -O https://nmap.org/npcap/dist/npcap-sdk-1.06.zip