2.7.2rc4: Feature improvements

What's Changed

• [2.7] Fix TLS corruption by replacing fork with posix_spawn (#3856) by @GeorgeWang-nv in #3983
• [2.7] Temporally remove pre install tool and example from 2.7 branch by @chesterxgchen in #3986
• [2.7] multinode guide for llm_hf by @ZiyueXu77 in #3991
• [2.7] Convert MONAI examples to Recipe by @holgerroth in #3971
• [2.7] Cherrypick from main: Fix docs [skip ci] (#3974) by @pcnudde in #3992
• [2.7] BioNeMo Task Fitting with PyTorch by @holgerroth in #3982
• [2.7] Cherry Pick Comprehensively remove mention of SAG by @nvkevlu in #3997
• [2.7] Cherry pick Make updates to Client API tutorials by @nvkevlu in #3995
• [2.7] Update web page and bump dependencies for security fixes by @nvkevlu in #3999
• [2.7] Cherry pick Add recipe for xgboost by @nvkevlu in #3994
• [2.7] Ignore downloder no ref_id errors by @nvidianz in #4004
• [2.7] Cherry Pick Fix hello-numpy-cross-val example by @nvkevlu in #3998
• [2.7] FedAvg Merge with FedAvgEarlyStopping + InTimeAggregation by @chesterxgchen in #3993

Full Changelog: 2.7.2rc3...2.7.2rc4