systemtests: add perpendicular-flap solid-openfoam and solid-fenics cases (refs #448)

[AdityaGupta716]

What this PR does

Adds two missing perpendicular-flap case combinations to the system tests:

• {fluid-openfoam, solid-openfoam} → added to openfoam_adapter_pr and release_test
• {fluid-openfoam, solid-fenics} → added to fenics_test and release_test

Refs #448

Checklist

• I added a summary of any user-facing changes in changelog-entries/448.md
• I will remember to squash-and-merge with a useful summary

[AdityaGupta716]

Added {fluid-openfoam, solid-openfoam} and {fluid-openfoam, solid-fenics} to the system tests , covering two of the first-priority cases listed in #448 . Reference results need to be generated via CI. @MakisH happy to trigger that if you can point me to the right workflow.