2.8.0rc3: Bug fixes and document updates

What's Changed

• [2.8] Add NVFlare CLI tutorial by @chesterxgchen in #4639
• [2.8] Avoid logging numpy trainer weights by @YuanTingHsieh in #4644
• [2.8] Clarify Docker deployment docs by @YuanTingHsieh in #4645
• [2.8] Backport K8s image pull secret support by @pcnudde in #4648
• [2.8]: Add more details on helm chart and k8s deployment guides [skip ci] by @IsaacYangSLA in #4646
• [2.8] Fix slow integration recipe tests by @YuanTingHsieh in #4652
• [2.8] Fix CC runtime workspace path by @nvidianz in #4649
• Add nSpect allowlist for 2.8 by @pcnudde in #4662
• Remove LGPL frontend dependencies by @chesterxgchen in #4664
• [2.8] Replace scikit-survival (GPL-3.0) with download_data.py in KM examples by @chesterxgchen in #4665
• [2.8] Move mobile samples out of package tree by @YuanTingHsieh in #4663
• [2.8] Add tensor disk offload to 2.8.0 release notes by @chesterxgchen in #4668
• [2.8] Fix NVFlare CLI docs by @chesterxgchen in #4670
• [2.8]: Lower a log level on one specific message by @IsaacYangSLA in #4674
• [2.8] fix fd leak in GenerateDataFromFile on send error by @chesterxgchen in #4675
• [2.8] Fix fstat fd leak in GenerateDataFromFile and add success-path test by @chesterxgchen in #4676
• [2.8] Add new examples to tutorial catalog by @chesterxgchen in #4672
• [2.8] Validate launcher_spec image field is a string by @nvshaxie in #4656
• [2.8] Auto-remove Docker job containers by @YuanTingHsieh in #4680

Full Changelog: 2.8.0rc2...2.8.0rc3