🧪💅 Mv reusable-windows workflow env to top

Previously, it was duplicated in each job which is not DRY.

Author: webknjaz

.github/workflows/reusable-windows.yml

@@ -7,13 +7,15 @@ on:
         type: boolean
         default: false
 
+env:
+  IncludeUwp: >-
+    true
+
 jobs:
   build_win32:
     name: 'build and test (x86)'
     runs-on: windows-latest
     timeout-minutes: 60
-    env:
-      IncludeUwp: 'true'
     steps:
     - uses: actions/checkout@v4
     - name: Build CPython
@@ -27,8 +29,6 @@ jobs:
     name: 'build and test (x64)'
     runs-on: windows-latest
     timeout-minutes: 60
-    env:
-       IncludeUwp: 'true'
     steps:
     - uses: actions/checkout@v4
     - name: Register MSVC problem matcher
@@ -44,8 +44,6 @@ jobs:
     name: 'build (arm64)'
     runs-on: windows-latest
     timeout-minutes: 60
-    env:
-      IncludeUwp: 'true'
     steps:
     - uses: actions/checkout@v4
     - name: Register MSVC problem matcher