[dynarmic] fix constexpr build issue on gcc-debian-stable (#3798)

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3798
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/dynarmic/src/dynarmic/backend/arm64/fastmem.h

@@ -29,7 +29,7 @@ constexpr size_t xmrx(size_t x) noexcept {
 }
 
 struct DoNotFastmemMarkerHash {
-    [[nodiscard]] constexpr size_t operator()(const DoNotFastmemMarker& value) const noexcept {
+    [[nodiscard]] size_t operator()(const DoNotFastmemMarker& value) const noexcept {
         return xmrx(std::get<0>(value).Value() ^ u64(std::get<1>(value)));
     }
 };