Astro 3.3: Picture component

Astro 3.3 introduces a new experimental Picture component, improvements to syntax highlighting, package provenance, and general quality of life improvements. Upgrading to Astro 3.3 can be done through the package manager of choice. The new Picture component generates a picture element with multiple source elements. The Image component now supports srcset and new properties have been added to generate a srcset attribute. Astro's internal syntax highlighter library has been migrated to shikiji. NPM has introduced optional provenance attestations for improved supply-chain security and transparency. The release also includes bug fixes and other quality of life improvements.