chore(astro): Add Astro integration keywords (#9193)

Adding [specific
keywords](https://docs.astro.build/en/reference/publish-to-npm/#integrations-library)
to an NPM package makes them show up in [Astro's integration library
page](https://astro.build/integrations/). This PR adds them to the Astro
package.json.

ref #9182

packages/astro/package.json

@@ -4,6 +4,12 @@
   "description": "Official Sentry SDK for Astro",
   "repository": "git://github.com/getsentry/sentry-javascript.git",
   "homepage": "https://github.com/getsentry/sentry-javascript/tree/master/packages/astro",
+  "keywords": [
+    "withastro",
+    "astro-component",
+    "sentry",
+    "apm"
+  ],
   "author": "Sentry",
   "license": "MIT",
   "engines": {