fix: Test the current Windows Dockerfile, not an old Dockerhub image

A bit infuriating that when you submit a PR modifying the Windows
cross-compilation script, the CI *builds* the current image in one job,
but then *runs* an older (!) image from Dockerhub in another. So it
tests that the modified image builds successfully but doesn't test if it
runs successfully, instead testing if an older image runs successfully /
testing if the current toxcore changes run successfully in an older
image.

This should build and run the same image with the current changes.

.github/scripts/cmake-windows.sh

@@ -26,4 +26,6 @@ docker run \
   -v "$PWD:/toxcore" \
   -v "$PWD/result:/prefix" \
   --rm \
+  -t \
+  --pull never \
   "toxchat/windows:$WINDOWS_ARCH"

.github/workflows/ci.yml

@@ -83,7 +83,7 @@ jobs:
       - name: Build and test
         run: .github/scripts/cmake-osx
 
-  build-msvc:
+  build-windows-msvc:
     strategy:
       matrix:
         version: [2019, 2022]
@@ -110,18 +110,6 @@ jobs:
           cd _build
           ctest -j50 --output-on-failure --rerun-failed --repeat until-pass:6 --build-config Debug
 
-  build-windows:
-    strategy:
-      matrix:
-        bits: [32, 64]
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          submodules: recursive
-      - name: Cross compilation
-        run: .github/scripts/cmake-win${{ matrix.bits }} script
-
   build-netbsd:
     runs-on: ubuntu-latest
     steps:

.github/workflows/docker.yml

@@ -138,9 +138,15 @@ jobs:
           cache-from: type=registry,ref=toxchat/c-toxcore:esp32
           cache-to: type=inline
 
-  docker-win32:
+  docker-windows-mingw:
+    strategy:
+      matrix:
+        bits: [32, 64]
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       - name: Login to DockerHub
@@ -149,39 +155,27 @@ jobs:
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
-      - name: Build and push
+      - name: Build and store to local Docker daemon
         uses: docker/build-push-action@v5
         with:
-          context: "{{defaultContext}}:other/docker/windows"
-          push: ${{ github.event_name == 'push' }}
-          tags: toxchat/windows:win32
-          cache-from: type=registry,ref=toxchat/windows:win32
-          cache-to: type=inline
+          context: other/docker/windows
+          load: true
+          tags: toxchat/windows:win${{ matrix.bits }}
+          cache-from: type=registry,ref=toxchat/windows:win${{ matrix.bits }}
           build-args: |
-            SUPPORT_ARCH_i686=true
-            SUPPORT_ARCH_x86_64=false
+            SUPPORT_ARCH_i686=${{ matrix.bits == '32' }}
+            SUPPORT_ARCH_x86_64=${{ matrix.bits == '64' }}
             SUPPORT_TEST=true
-
-  docker-win64:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-      - name: Login to DockerHub
+      - name: Push the stored image to Dockerhub
         if: ${{ github.event_name == 'push' }}
-        uses: docker/login-action@v3
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-      - name: Build and push
         uses: docker/build-push-action@v5
         with:
-          context: "{{defaultContext}}:other/docker/windows"
+          context: other/docker/windows
           push: ${{ github.event_name == 'push' }}
-          tags: toxchat/windows:win64
-          cache-from: type=registry,ref=toxchat/windows:win64
-          cache-to: type=inline
+          tags: toxchat/windows:win${{ matrix.bits }}
           build-args: |
-            SUPPORT_ARCH_i686=false
-            SUPPORT_ARCH_x86_64=true
+            SUPPORT_ARCH_i686=${{ matrix.bits == '32' }}
+            SUPPORT_ARCH_x86_64=${{ matrix.bits == '64' }}
             SUPPORT_TEST=true
+      - name: Cross-compile
+        run: .github/scripts/cmake-win${{ matrix.bits }} script