Update dependency shoulda-matchers to v6.4.0

Gemfile.lock

@@ -90,7 +90,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.2.3)
+    concurrent-ruby (1.3.4)
     crass (1.0.6)
     date (3.3.4)
     diff-lcs (1.5.1)
@@ -130,7 +130,7 @@ GEM
     method_source (1.0.0)
     mini_mime (1.1.5)
     mini_portile2 (2.8.7)
-    minitest (5.22.3)
+    minitest (5.25.1)
     msgpack (1.7.2)
     mysql2 (0.5.6)
     net-imap (0.3.7)
@@ -230,7 +230,7 @@ GEM
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
     semantic_range (3.0.0)
-    shoulda-matchers (6.2.0)
+    shoulda-matchers (6.4.0)
       activesupport (>= 5.2.0)
     simplecov (0.22.0)
       docile (~> 1.1)
@@ -281,7 +281,7 @@ GEM
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.6.16)
+    zeitwerk (2.6.17)
 
 PLATFORMS
   ruby