[flat.set.defn] Remove superfluous whitespace (#8686)

Author: Andreas-Krug

source/containers.tex

@@ -19016,19 +19016,19 @@
   class @\libglobal{flat_set}@ {
   public:
     // types
-    using key_type                  = Key;
-    using value_type                = Key;
-    using key_compare               = Compare;
-    using value_compare             = Compare;
-    using reference                 = value_type&;
-    using const_reference           = const value_type&;
-    using size_type                 = KeyContainer::size_type;
-    using difference_type           = KeyContainer::difference_type;
-    using iterator                  = @\impdefx{type of \tcode{flat_set::iterator}}@;  // see \ref{container.requirements}
-    using const_iterator            = @\impdefx{type of \tcode{flat_set::const_iterator}}@;  // see \ref{container.requirements}
-    using reverse_iterator          = std::reverse_iterator<iterator>;
-    using const_reverse_iterator    = std::reverse_iterator<const_iterator>;
-    using container_type            = KeyContainer;
+    using key_type               = Key;
+    using value_type             = Key;
+    using key_compare            = Compare;
+    using value_compare          = Compare;
+    using reference              = value_type&;
+    using const_reference        = const value_type&;
+    using size_type              = KeyContainer::size_type;
+    using difference_type        = KeyContainer::difference_type;
+    using iterator               = @\impdefx{type of \tcode{flat_set::iterator}}@;     // see \ref{container.requirements}
+    using const_iterator         = @\impdefx{type of \tcode{flat_set::const_iterator}}@;     // see \ref{container.requirements}
+    using reverse_iterator       = std::reverse_iterator<iterator>;
+    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+    using container_type         = KeyContainer;
 
     // \ref{flat.set.cons}, constructors
     constexpr flat_set() : flat_set(key_compare()) { }