Revert "Update ci.yml"

This reverts commit 4a52bb0.

Author: ViralBShah

.github/workflows/ci.yml

@@ -25,20 +25,15 @@ jobs:
     - run: make test
 
   buildwindows:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        include:
-          - { sys: mingw64, env: x86_64 }
-          - { sys: mingw32, env: i686 }
+    runs-on: windows-latest
     defaults:
       run:
         shell: msys2 {0}
     steps:
     - uses: actions/checkout@v2
     - uses: msys2/setup-msys2@v2
       with: 
-        msystem: ${{matrix.sys}}
-        install: make mingw-w64-${{matrix.env}}-toolchain
+        msystem: MINGW64
+        install: make mingw-w64-x86_64-toolchain
     - run: make
     - run: make test