Bump fastimage from 2.2.5 to 2.2.6 (#15806)

Bumps [fastimage](https://github.com/sdsykes/fastimage) from 2.2.5 to 2.2.6.
- [Release notes](https://github.com/sdsykes/fastimage/releases)
- [Changelog](https://github.com/sdsykes/fastimage/blob/master/CHANGELOG)
- [Commits](https://github.com/sdsykes/fastimage/compare/v2.2.5...v2.2.6)

---
updated-dependencies:
- dependency-name: fastimage
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -280,7 +280,7 @@ GEM
     faraday-net_http_persistent (1.2.0)
     faraday-patron (1.0.0)
     faraday-rack (1.0.0)
-    fastimage (2.2.5)
+    fastimage (2.2.6)
     fastly (3.0.2)
     feedjira (3.2.0)
       loofah (>= 2.3.1)