Bump aws-sdk-core from 3.218.0 to 3.218.1

Bumps [aws-sdk-core](https://github.com/aws/aws-sdk-ruby) from 3.218.0 to 3.218.1.
- [Release notes](https://github.com/aws/aws-sdk-ruby/releases)
- [Changelog](https://github.com/aws/aws-sdk-ruby/blob/version-3/gems/aws-sdk-core/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-ruby/commits)

---
updated-dependencies:
- dependency-name: aws-sdk-core
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

gems.locked

@@ -2,12 +2,13 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
-    aws-eventstream (1.3.0)
-    aws-partitions (1.1047.0)
-    aws-sdk-core (3.218.0)
+    aws-eventstream (1.3.1)
+    aws-partitions (1.1050.0)
+    aws-sdk-core (3.218.1)
       aws-eventstream (~> 1, >= 1.3.0)
       aws-partitions (~> 1, >= 1.992.0)
       aws-sigv4 (~> 1.9)
+      base64
       jmespath (~> 1, >= 1.6.1)
     aws-sdk-kms (1.98.0)
       aws-sdk-core (~> 3, >= 3.216.0)