astro 1.0.0-beta.45

#3593 0e2314d8 Thanks @matthewp! - Fixes uses of inline hoisted scripts in SSR
#3590 d46f8fb1 Thanks @okikio! - Add support for optional integrations

By making integration optional, Astro can now ignore null, undefined or other falsy "Integration" values instead of giving an internal error most devs can't and/or won't understand.

This also enables conditional integrations, e.g.
```
integration: [
  // Only run `compress` integration when in production environments, etc...
  import.meta.env.production ? compress() : null,
];
```