AK: Remove StringBuilder::build() in favor of to_deprecated_string()

Having an alias function that only wraps another one is silly, and
keeping the more obvious name should flush out more uses of deprecated
strings.
No behavior change.

Userland/Libraries/LibC/semaphore.cpp

@@ -48,7 +48,7 @@ static ErrorOr<DeprecatedString> sem_name_to_path(char const* name)
     StringBuilder builder;
     TRY(builder.try_append(sem_path_prefix));
     TRY(builder.try_append(name_view));
-    return builder.build();
+    return builder.to_deprecated_string();
 }
 
 struct NamedSemaphore {

Userland/Libraries/LibC/stdlib.cpp

@@ -641,7 +641,7 @@ int ptsname_r(int fd, char* buffer, size_t size)
         return -1;
     }
     memset(buffer, 0, devpts_path_builder.length() + 1);
-    auto full_devpts_path_string = devpts_path_builder.build();
+    auto full_devpts_path_string = devpts_path_builder.to_deprecated_string();
     if (!full_devpts_path_string.copy_characters_to_buffer(buffer, size)) {
         errno = ERANGE;
         return -1;

Userland/Libraries/LibC/syslog.cpp

@@ -124,7 +124,7 @@ void vsyslog_r(int priority, struct syslog_data* data, char const* message, va_l
         combined.appendff("{}: ", get_syslog_ident(data));
 
     combined.appendvf(message, args);
-    DeprecatedString combined_string = combined.build();
+    auto combined_string = combined.to_deprecated_string();
 
     if (data->logopt & LOG_CONS)
         dbgputstr(combined_string.characters(), combined_string.length());

Userland/Libraries/LibC/time.cpp

@@ -390,7 +390,7 @@ size_t strftime(char* destination, size_t max_size, char const* format, const st
             return 0;
     }
 
-    auto str = builder.build();
+    auto str = builder.to_deprecated_string();
     bool fits = str.copy_characters_to_buffer(destination, max_size);
     return fits ? str.length() : 0;
 }