Update charlock_holmes to v0.7.7

charlock_holmes v0.7.7 resolves a C++ build issue
(https://github.com/brianmario/charlock_holmes/compare/0.7.6..v0.7.7) on
some machines.

This may also resolve a CentOS 6 build issue
(https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5682) since the
gem will be available for gitaly-ruby using the newer compiler.

Gemfile

@@ -272,7 +272,7 @@ gem 'licensee', '~> 8.9'
 gem 'ace-rails-ap', '~> 4.1.0'
 
 # Detect and convert string character encoding
-gem 'charlock_holmes', '~> 0.7.5'
+gem 'charlock_holmes', '~> 0.7.7'
 
 # Detect mime content type from content
 gem 'mimemagic', '~> 0.3.2'

Gemfile.lock

@@ -167,7 +167,7 @@ GEM
       mime-types (>= 1.16)
     cbor (0.5.9.6)
     character_set (1.4.0)
-    charlock_holmes (0.7.6)
+    charlock_holmes (0.7.7)
     childprocess (3.0.0)
     chunky_png (1.3.5)
     citrus (3.0.2)
@@ -1270,7 +1270,7 @@ DEPENDENCIES
   capybara (~> 3.33.0)
   capybara-screenshot (~> 1.0.22)
   carrierwave (~> 1.3)
-  charlock_holmes (~> 0.7.5)
+  charlock_holmes (~> 0.7.7)
   commonmarker (~> 0.20)
   concurrent-ruby (~> 1.1)
   connection_pool (~> 2.0)