devel/pecl-vld: Fix build with php84 (8.4.0beta3+)

Obtained from: https://github.com/derickr/vld/commit/dc56f73a25b0230745afb5523871f2e8dd33fccd
Reference: https://pkg-status.freebsd.org/beefy22/data/140amd64-default/b3cf46924d98/logs/php84-pecl-vld-0.18.0.log