Some backports into master

This MR backports (to the master branch) 3 commits already merged into the surface_model branch:

• Fix gcc 12.3.0 warnings (see MR !1047 (merged))
• Fix TestBVHNavigator compilation warning (see MR !1058 (merged))
• Make the GDML validation optional, according to command line argument (see MR !1082 (merged), commit 7b396f1a)