CMake: Change core install location to lib/libretro (#1842)

* CMake: Change core install location to lib/libretro

* fix CI build artifacts location

---------

Co-authored-by: Andrew Wong <wongandj@icloud.com>
Co-authored-by: Flyinghead <raphael.jean@gmail.com>

.github/workflows/c-cpp.yml

@@ -129,7 +129,9 @@ jobs:
       - uses: actions/upload-artifact@v4
         with:
           name: flycast-${{ matrix.config.name }}
-          path: artifact/bin
+          path: |
+            artifact/bin
+            artifact/lib/libretro
 
       - name: Package app (macos)
         run: |
@@ -179,4 +181,4 @@ jobs:
         env:
           SENTRY_TOKEN: ${{ secrets.SENTRY_TOKEN }}
         if: ${{ env.SENTRY_TOKEN != '' && (matrix.config.name == 'x86_64-w64-mingw32' || matrix.config.name == 'apple-darwin' || matrix.config.name == 'x86_64-pc-linux-gnu') }}
-        
+        

CMakeLists.txt

@@ -1929,6 +1929,8 @@ if(IOS)
 	install(FILES "${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>-${CMAKE_OSX_SYSROOT}/Flycast.ipa" TYPE BIN)
 elseif(NINTENDO_SWITCH AND NOT LIBRETRO)
 	install(FILES ${CMAKE_BINARY_DIR}/flycast.nro DESTINATION "${CMAKE_INSTALL_BINDIR}")
+elseif(LIBRETRO)
+	install(TARGETS ${PROJECT_NAME} DESTINATION "${CMAKE_INSTALL_LIBDIR}/libretro")
 else()
 	install(TARGETS ${PROJECT_NAME} DESTINATION "${CMAKE_INSTALL_BINDIR}")
 endif()