Fix typos

Author: rhpvorderman

.github/workflows/ci.yml

@@ -65,10 +65,10 @@ jobs:
         run: pip install --upgrade tox setuptools pip
       - name: Install build dependencies (Linux)  # Yasm in pypa/manylinux images.
         run: sudo apt install yasm
-        if: ${{ runner.os == "Linux" }}
+        if: ${{ runner.os == "linux" }}
       - name: Install build dependencies (Macos)
         run: brew install yasm automake autoconf
-        if: ${{ runner.os == "MacOS" }}
+        if: ${{ runner.os == "macOS" }}
       - name: Install build dependencies (Windows)
         run: choco install yasm
         if: ${{ runner.os == "Windows" }}