Bump fastly from 15.0.0 to 15.1.0

Bumps [fastly](https://github.com/fastly/fastly-ruby) from 15.0.0 to 15.1.0.
- [Release notes](https://github.com/fastly/fastly-ruby/releases)
- [Changelog](https://github.com/fastly/fastly-ruby/blob/main/CHANGELOG.md)
- [Commits](fastly/fastly-ruby@release/v15.0.0...release/v15.1.0)

---
updated-dependencies:
- dependency-name: fastly
  dependency-version: 15.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Gemfile.lock

@@ -184,7 +184,7 @@ GEM
       faraday-net_http (>= 2.0, < 3.1)
       ruby2_keywords (>= 0.0.4)
     faraday-net_http (3.0.2)
-    fastly (15.0.0)
+    fastly (15.1.0)
       typhoeus (~> 1.0, >= 1.0.1)
     ffi (1.17.2)
     foreman (0.90.0)