Github workflows : Update Windows build to MSVC 2019

- Update Window dependencies to 6.0.0.

Author: ericmehl

.github/workflows/main.yml

@@ -75,6 +75,22 @@ jobs:
             tests: testCore testCorePython testScene testImage testAlembic testUSD testVDB
             publish: true
 
+          - name: windows-python3
+            os: windows-2019
+            buildType: RELEASE
+            options: .github/workflows/main/options.windows
+            dependenciesURL: https://github.com/hypothetical-inc/gafferDependencies/releases/download/6.0.0/gafferDependencies-6.0.0-Python3-windows.zip
+            tests: testCore testCorePython testScene testImage testAlembic testUSD testVDB
+            publish: false
+
+          - name: windows-python3-debug
+            os: windows-2019
+            buildType: RELWITHDEBINFO
+            options: .github/workflows/main/options.windows
+            dependenciesURL: https://github.com/hypothetical-inc/gafferDependencies/releases/download/6.0.0/gafferDependencies-6.0.0-Python3-windows.zip
+            tests: testCore testCorePython testScene testImage testAlembic testUSD testVDB
+            publish: false
+
     runs-on: ${{ matrix.os }}
 
     container: ${{ matrix.containerImage }}