[wp] discard trivial tasks

src/plugins/wp/ProverWhy3.ml

...gins/wp/tests/wp_acsl/oracle_qualif/e_imply.0.report.json

...plugins/wp/tests/wp_acsl/oracle_qualif/e_imply.res.oracle

...ugins/wp/tests/wp_acsl/oracle_qualif/sizeof.0.report.json

src/plugins/wp/tests/wp_bts/oracle_qualif/bts0843.res.oracle

...ins/wp/tests/wp_bts/oracle_qualif/issue_447.0.report.json

...lugins/wp/tests/wp_bts/oracle_qualif/issue_447.res.oracle