chore: properly deallocate OAM buffer

src/ppu.zig

@@ -71,6 +71,7 @@ pub const Ppu = struct {
         self.alloc.free(self.framebuf);
         self.vram.deinit();
         self.palette.deinit();
+        self.oam.deinit();
     }
 
     pub fn setBgOffsets(self: *Self, comptime n: u3, word: u32) void {
@@ -517,6 +518,10 @@ const Oam = struct {
         };
     }
 
+    fn deinit(self: Self) void {
+        self.alloc.free(self.buf);
+    }
+
     pub fn get32(self: *const Self, idx: usize) u32 {
         return (@as(u32, self.buf[idx + 3]) << 24) | (@as(u32, self.buf[idx + 2]) << 16) | (@as(u32, self.buf[idx + 1]) << 8) | (@as(u32, self.buf[idx]));
     }