v0.9.0 - Configurable Head Nodes and Stability

What's Changed

• Configure head by @MichaelClifford in #354
• Check for dashboard readiness after cluster is ready by @ChristianZaccaria in #356
• Remove pytorch-lightning dep by @Maxusmusti in #360
• [Automatic] Coverage Badge Update by @github-actions in #361
• Added approvers dimakis & Bobbins228 by @Bobbins228 in #367
• build: update python to v3.9 and ray to v2.7 by @dimakis in #377
• update ray version in default template and code references by @KPostOffice in #379
• Changes in docs for release: v0.9.0 by @codeflare-machine-account in #381

Full Changelog: v0.8.0...v0.9.0