Trophy: Replace sdl mixer library with minimp3 header for playing trophy sounds (#4261)

* Replace sdl mixer library with minimp3 header

* clang

* set spec before putting in audiostream

* respect main audio output device setting

* fixup

* replace file with submodule

* cleanup

* capitalize functions like the others

* move buffer to heap

* use vector for pcm buffer instead

.gitmodules

@@ -106,10 +106,6 @@
 [submodule "externals/json"]
 	path = externals/json
 	url = https://github.com/nlohmann/json.git
-[submodule "externals/sdl3_mixer"]
-	path = externals/sdl3_mixer
-	url = https://github.com/libsdl-org/SDL_mixer
-	shallow = true
 [submodule "externals/miniz"]
 	path = externals/miniz
 	url = https://github.com/richgel999/miniz
@@ -136,3 +132,7 @@
 	path = externals/libusb
 	url = https://github.com/shadexternals/libusb.git
 	branch = shadps4
+[submodule "externals/minimp3"]
+	path = externals/minimp3
+	url = https://github.com/lieff/minimp3
+	shallow = true