Set min sdk to 31

Author: iscle

.github/workflows/build.yml

@@ -3,7 +3,7 @@ name: build
 on: [push, pull_request]
 
 env:
-  MIN_SDK_VERSION: 21
+  MIN_SDK_VERSION: 31
 
 jobs:
   build:
@@ -19,7 +19,7 @@ jobs:
 
       - name: Build with CMake
         run: |
-          cmake -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake -DANDROID_ABI=${{ matrix.abi }} -DANDROID_PLATFORM=android-${{ env.MIN_SDK_VERSION }} -DANDROID_ARM_NEON=TRUE .
+          cmake -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake -DANDROID_ABI=${{ matrix.abi }} -DANDROID_PLATFORM=android-${{ env.MIN_SDK_VERSION }} -DANDROID_ARM_NEON=true .
           cmake --build . -- -j$(nproc)
 
       - name: Upload artifacts