Bump rack-session from 2.1.1 to 2.1.2 (#336)

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

Author: dependabot[bot]

Gemfile.lock

@@ -301,7 +301,7 @@ GEM
       nio4r (~> 2.0)
     racc (1.8.1)
     rack (3.2.6)
-    rack-session (2.1.1)
+    rack-session (2.1.2)
       base64 (>= 0.1.0)
       rack (>= 3.0.0)
     rack-test (2.2.0)