Update package:equatable pin (#47475)

flutter/flutter#137557

Author: zanderso

DEPS

@@ -639,7 +639,7 @@ deps = {
   Var('github_git') + '/brendan-duncan/archive.git' + '@' + '9de7a0544457c6aba755ccb65abb41b0dc1db70d', # 3.1.2
 
   'src/third_party/pkg/equatable':
-  Var('github_git') + '/felangel/equatable.git' + '@' + '0ba67c72db8bed75877fc1caafa74112ee0bd921', # 2.0.2
+  Var('github_git') + '/felangel/equatable.git' + '@' + '2117551ff3054f8edb1a58f63ffe1832a8d25623', # 2.0.5
 
   'src/third_party/pkg/flutter_packages':
   Var('flutter_git') + '/mirrors/packages' + '@' + '25454e63851fe7933f04d025606e68c1eac4fe0f', # various