ci: Compile-test sys and windows crate on Linux target (Ubuntu)

Author: MarijnS95

.github/workflows/build.yml

@@ -46,10 +46,13 @@ jobs:
 
   cargo_sys:
     name: Check windows-sys
-    runs-on: windows-2019
     strategy:
       matrix:
         rust: [1.46.0, stable, nightly]
+        runs-on:
+          - windows-2019
+          - ubuntu-latest
+    runs-on: ${{ matrix.runs-on }}
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -60,10 +63,13 @@ jobs:
 
   cargo_windows:
     name: Check windows
-    runs-on: windows-2019
     strategy:
       matrix:
         rust: [1.59.0, stable, nightly]
+        runs-on:
+          - windows-2019
+          - ubuntu-latest
+    runs-on: ${{ matrix.runs-on }}
     steps:
     - name: Checkout
       uses: actions/checkout@v2

crates/tools/yml/src/main.rs

@@ -186,10 +186,13 @@ jobs:
 
   cargo_sys:
     name: Check windows-sys
-    runs-on: windows-2019
     strategy:
       matrix:
         rust: [1.46.0, stable, nightly]
+        runs-on:
+          - windows-2019
+          - ubuntu-latest
+    runs-on: ${{ matrix.runs-on }}
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -200,10 +203,13 @@ jobs:
 
   cargo_windows:
     name: Check windows
-    runs-on: windows-2019
     strategy:
       matrix:
         rust: [1.59.0, stable, nightly]
+        runs-on:
+          - windows-2019
+          - ubuntu-latest
+    runs-on: ${{ matrix.runs-on }}
     steps:
     - name: Checkout
       uses: actions/checkout@v2