tests: Use g_memdup2
../tests/gvdb.c: In function ‘test_corrupted’:
../tests/gvdb.c:364:7: error: ‘g_memdup’ is deprecated: Use 'g_memdup2' instead [-Werror=deprecated-declarations]
364 | copy = g_memdup (orig, length);
| ^~~~
../tests/gvdb.c: In function ‘test_corrupted’:
../tests/gvdb.c:364:7: error: ‘g_memdup’ is deprecated: Use 'g_memdup2' instead [-Werror=deprecated-declarations]
364 | copy = g_memdup (orig, length);
| ^~~~