Bump gds-sso from 18.0.0 to 18.1.0

Bumps [gds-sso](https://github.com/alphagov/gds-sso) from 18.0.0 to 18.1.0.
- [Changelog](https://github.com/alphagov/gds-sso/blob/main/CHANGELOG.md)
- [Commits](alphagov/gds-sso@v18.0.0...v18.1.0)

---
updated-dependencies:
- dependency-name: gds-sso
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -160,7 +160,7 @@ GEM
       null_logger
       plek (>= 1.9.0)
       rest-client (~> 2.0)
-    gds-sso (18.0.0)
+    gds-sso (18.1.0)
       oauth2 (~> 2.0)
       omniauth (~> 2.1)
       omniauth-oauth2 (~> 1.8)
@@ -502,8 +502,8 @@ GEM
     raabro (1.4.0)
     racc (1.7.1)
     rack (2.2.8)
-    rack-protection (3.0.6)
-      rack
+    rack-protection (3.1.0)
+      rack (~> 2.2, >= 2.2.4)
     rack-proxy (0.7.6)
       rack
     rack-test (2.1.0)