Address the feedback

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs

@@ -32,8 +32,6 @@ public sealed partial class TimeZoneInfo
             "Zulu"
         };
 
-        private static readonly TimeZoneInfo s_utcTimeZone = CreateUtcTimeZone();
-
         private TimeZoneInfo(byte[] data, string id, bool dstDisabled)
         {
             _id = id;

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Win32.cs

@@ -35,8 +35,6 @@ public sealed partial class TimeZoneInfo
         private const int MaxKeyLength = 255;
         private const string InvariantUtcStandardDisplayName = "Coordinated Universal Time";
 
-        private static readonly TimeZoneInfo s_utcTimeZone = CreateUtcTimeZone();
-
         private sealed partial class CachedData
         {
             private static TimeZoneInfo GetCurrentOneYearLocal()
@@ -739,7 +737,7 @@ private static bool TryCompareTimeZoneInformationToRegistry(in TIME_ZONE_INFORMA
 
 
         /// <summary>
-        /// Try to find the time zone resources Dll matching the CurrentUICulture or on eof its parent cultures.
+        /// Try to find the time zone resources Dll matching the CurrentUICulture or one of its parent cultures.
         /// We try to check of such resource module e.g. %windir%\system32\[UI Culture Name]\tzres.dll.mui exist.
         /// If a localized resource file exists, we LoadString resource with the id specified inside resource input
         /// string and and return it to our caller.
@@ -775,8 +773,8 @@ private static string GetLocalizedNameByMuiNativeResource(string resource)
             // get the path to Windows\System32
             string system32 = Environment.SystemDirectory;
 
-            // trim the string "@tzres.dll" => "tzres.dll"
-            string tzresDll = resources[0].TrimStart('@') + ".mui";
+            // trim the string "@tzres.dll" to "tzres.dll" and append the "mui" file extension to it.
+            string tzresDll = $"{resources[0].AsSpan().TrimStart('@')}.mui";
 
             try
             {

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs

@@ -53,6 +53,7 @@ private enum TimeZoneInfoResult
         private const string UtcId = "UTC";
         private const string LocalId = "Local";
 
+        private static readonly TimeZoneInfo s_utcTimeZone = CreateUtcTimeZone();
         private static CachedData s_cachedData = new CachedData();
 
         //