Add GitHub Actions workflow for ABE decryption build

.github/workflows/main.yml

@@ -0,0 +1,42 @@
+name: Build ABE Decryption
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - shell: pwsh
+        run: |
+          python -m pip install --upgrade pip
+          if (Test-Path "requirements.txt") { pip install -r requirements.txt }
+
+      - uses: ilammy/msvc-dev-cmd@v1
+        with:
+          arch: x64
+
+      - shell: pwsh
+        run: |
+          where cl
+          cl
+
+      - shell: pwsh
+        run: python builder.py
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: build-output
+          path: |
+            build/
+            *.dll
+            *.exe