Remove deprecated strfttime in NodaTimeSplitter

src/NodaTimeSplitter.php

@@ -242,17 +242,31 @@ final class NodaTimeSplitter {
         if ($moda[0] !== $moda[1]) {
             return "{$prefix}{$moda[0]}-{$moda[1]}{$suffix}";
         }
+
+        // A single day of a given month of a given (single) year
         else if (\intval($moda[2]) !== 0 and \intval($moda[3]) !== 0) {
             return "{$prefix}{$moda[3]}.{$moda[2]}.{$moda[0]}{$suffix}";
         }
+
+        // A single year
         else if ($moda[0] === $moda[1] && trim((string)$moda[2], " 0") === "" && trim((string)$moda[3], " 0") === "") {
             return "{$prefix}{$moda[0]}{$suffix}";
         }
+
+        // Single month of a given year
         else if ($moda[0] === $moda[1] && trim((string)$moda[2], " 0") !== "" && trim((string)$moda[3], " 0") === "") {
-            setlocale(LC_TIME, NodaTimeAutotranslater::LANGS_TO_LOCALES['de']);
+
+            $fmt = new IntlDateFormatter(
+                'de-DE',
+                IntlDateFormatter::FULL,
+                IntlDateFormatter::FULL,
+                null,
+                IntlDateFormatter::GREGORIAN,
+                'MMMM Y'
+            );
 
             try {
-                return $prefix . strftime(getMonthFormatByLang("de"), MD_STD::strtotime("{$moda[0]}-{$moda[2]}-01 01:01:01")) . $suffix;
+                return $prefix . $fmt->format(MD_STD::strtotime("{$moda[0]}-{$moda[2]}-10 01:01:01")) . $suffix;
             }
             catch (MDInvalidInputDate $e) {
                 return "";