Release 2.7.2rc5: bug fixes · NVIDIA/NVFlare

What's Changed

[2.7] Mandating signature by @IsaacYangSLA in #4008
[2.7] Fix NumPy CSE regression in 2.7.2rc4 by @nvkevlu in #4011
[2.7] handle non exists file with absolute file path by @chesterxgchen in #4007
[2.7] Cherry pick Add Recipe for Experiment Tracking by @nvkevlu in #4009
[2.7] Release news and feature highlights, doc restructure [skip ci] by @chesterxgchen in #4017
[2.7] Update LR related examples by @YuanTingHsieh in #4014
[2.7] Update product feature docs [skip ci] by @chesterxgchen in #4018
[2.7] Fix sklearn examples by @YuanTingHsieh in #4015
[2.7] Increase link check timeout by @holgerroth in #4027
[2.7] Convert AMPLIFY example to recipe by @holgerroth in #4022
[2.7] Recipe site configuration [skip ci] by @chesterxgchen in #4021
[2.7] Add Brats to research by @ZiyueXu77 in #4026
[2.7] Fixed the swarm bug by @nvidianz in #4025
[2.7] Add recipes to init by @YuanTingHsieh in #4031
[2.7] Enhance weighted agg helper by @YuanTingHsieh in #4020
[2.7] Cherry pick 4002 4005 by @YuanTingHsieh in #4034
[2.7] Added origin to the stream lookup key by @nvidianz in #4033

Full Changelog: 2.7.2rc4...2.7.2rc5