[Security] Bump omniauth from 1.9.0 to 1.9.1 (#13229)

Bumps [omniauth](https://github.com/omniauth/omniauth) from 1.9.0 to 1.9.1. **This update includes a security fix.**
- [Release notes](https://github.com/omniauth/omniauth/releases)
- [Commits](https://github.com/omniauth/omniauth/compare/v1.9.0...v1.9.1)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile.lock

@@ -266,7 +266,7 @@ GEM
     hamster (3.0.0)
       concurrent-ruby (~> 1.0)
     hashdiff (1.0.1)
-    hashie (3.6.0)
+    hashie (4.1.0)
     highline (2.0.3)
     hiredis (0.6.3)
     hkdf (0.3.0)
@@ -384,8 +384,8 @@ GEM
       sidekiq (>= 3.5)
       statsd-ruby (~> 1.4, >= 1.4.0)
     oj (3.10.3)
-    omniauth (1.9.0)
-      hashie (>= 3.4.6, < 3.7.0)
+    omniauth (1.9.1)
+      hashie (>= 3.4.6)
       rack (>= 1.6.2, < 3)
     omniauth-cas (1.1.1)
       addressable (~> 2.3)