fix: upgrade gatsby-plugin-image from 3.0.0 to 3.12.3

Snyk has created this PR to upgrade gatsby-plugin-image from 3.0.0 to 3.12.3.

See this package in npm:
https://www.npmjs.com/package/gatsby-plugin-image

See this project in Snyk:
https://app.snyk.io/org/sammyfilly/project/4d0e3b9c-be4d-47f2-840c-b487311dd2e0?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

starters/gatsby-starter-wordpress-blog/package.json

@@ -12,7 +12,7 @@
     "@fontsource/montserrat": "^4.5.13",
     "@wordpress/block-library": "^7.18.0",
     "gatsby": "^5.0.0",
-    "gatsby-plugin-image": "^3.0.0",
+    "gatsby-plugin-image": "^3.12.3",
     "gatsby-plugin-manifest": "^5.0.0",
     "gatsby-plugin-sharp": "^5.0.0",
     "gatsby-source-wordpress": "^7.0.0",