fix(deps): update dependency astro to v7 [security] - #320

Changed pages include:

• index.html - view
• blog/index.html - view
• changelog/index.html - view
• frequently-asked-questions/index.html - view
• imprint/index.html - view
• blog/post/hello-world-my-name-is-sourcectl/index.html - view
• blog/post/login-with-github-and-act-on-your-behalf/index.html - view
• changelog/entry/2021-04-19-initial-commit/index.html - view
• changelog/entry/2021-04-26-repository-checks-open-source-best-practices/index.html - view
• changelog/entry/2021-04-28-repository-checks-social-preview-image/index.html - view

There are more changes not included in the list