Migrate bootstrap from grunt to vite

Bootstrap is currently build with grunt, which is badly deprecated.
We need to move it to vite to align with the rest of the npm builds.

Current analysis

• the less files are just copied and moved to when building xwiki-platform-flamingo-skin-resources, they just have to be placed at the same location with a copy
• iiuc the css and fonts are not used
• many css files bundled in the current webjar seems also unsed