Phase 2 Study of Ribociclib-Containing Post-Radiotherapy Combinations in Pediatric and Young Adult Patients Newly Diagnosed With High-Grade Glioma, Including Diffuse Intrinsic Pontine Glioma: Ribociclib and Everolimus for HGG/DIPG Which Harbor Alterations of the Cell Cycle and/or PI3K/mTOR Pathways AND Ribociclib and Temozolomide for DHG, H3G34-mutant | Arctuva