remove misguided addition to timezone try_from_string

Author: lockels

src/builtins/core/instant.rs

@@ -341,7 +341,7 @@ mod tests {
         options::{DifferenceSettings, TemporalRoundingMode, TemporalUnit},
         primitive::FiniteF64,
         time::EpochNanoseconds,
-        TimeZone, NS_MAX_INSTANT, NS_MIN_INSTANT,
+        NS_MAX_INSTANT, NS_MIN_INSTANT,
     };
 
     #[test]
@@ -607,15 +607,6 @@ mod tests {
         );
     }
 
-    #[test]
-    // timezone-case-insensitive.js
-    fn timezone_case_insensitive() {
-        let instance = Instant::try_new(0).unwrap();
-        let time_zone = TimeZone::try_from_str("uTc").unwrap();
-        let result = instance.to_zoned_date_time_iso(time_zone).unwrap();
-        assert_eq!(result.timezone().identifier().unwrap(), "UTC");
-    }
-
     // /test/built-ins/Temporal/Instant/prototype/add/cross-epoch.js
     #[cfg(feature = "tzdb")]
     #[test]

src/builtins/core/timezone.rs

@@ -105,8 +105,7 @@ impl TimeZone {
     }
 
     pub fn try_from_str(src: &str) -> TemporalResult<Self> {
-        let normalized = src.to_uppercase();
-        if let Ok(timezone) = Self::try_from_identifier_str(&normalized) {
+        if let Ok(timezone) = Self::try_from_identifier_str(src) {
             return Ok(timezone);
         }