fix: upgrade multiple dependencies with Snyk

Snyk has created this PR to upgrade:
  - gatsby from 5.0.0 to 5.12.9.
    See this package in npm: https://www.npmjs.com/package/gatsby
  - gatsby-plugin-manifest from 5.0.0 to 5.12.3.
    See this package in npm: https://www.npmjs.com/package/gatsby-plugin-manifest
  - gatsby-plugin-sharp from 5.0.0 to 5.12.3.
    See this package in npm: https://www.npmjs.com/package/gatsby-plugin-sharp
  - gatsby-source-wordpress from 7.0.0 to 7.12.3.
    See this package in npm: https://www.npmjs.com/package/gatsby-source-wordpress
  - gatsby-transformer-sharp from 5.0.0 to 5.12.3.
    See this package in npm: https://www.npmjs.com/package/gatsby-transformer-sharp

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

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

@@ -11,12 +11,12 @@
     "@fontsource/merriweather": "^4.5.14",
     "@fontsource/montserrat": "^4.5.13",
     "@wordpress/block-library": "^7.18.0",
-    "gatsby": "^5.0.0",
+    "gatsby": "^5.12.9",
     "gatsby-plugin-image": "^3.0.0",
-    "gatsby-plugin-manifest": "^5.0.0",
-    "gatsby-plugin-sharp": "^5.0.0",
-    "gatsby-source-wordpress": "^7.0.0",
-    "gatsby-transformer-sharp": "^5.0.0",
+    "gatsby-plugin-manifest": "^5.12.3",
+    "gatsby-plugin-sharp": "^5.12.3",
+    "gatsby-source-wordpress": "^7.12.3",
+    "gatsby-transformer-sharp": "^5.12.3",
     "html-react-parser": "^3.0.4",
     "lodash": "^4.17.21",
     "react": "^18.2.0",