Revert "Reuse NoTransactionInContextException instances"

This reverts commit 8e38469.

Closes gh-34048

Author: sdeleuze

spring-tx/src/main/java/org/springframework/transaction/reactive/TransactionContextManager.java

@@ -37,9 +37,6 @@
  */
 public abstract class TransactionContextManager {
 
-	private static final NoTransactionInContextException NO_TRANSACTION_IN_CONTEXT_EXCEPTION =
-			new NoTransactionInContextException();
-
 	private TransactionContextManager() {
 	}
 
@@ -63,7 +60,7 @@ public static Mono<TransactionContext> currentContext() {
 					return Mono.just(holder.currentContext());
 				}
 			}
-			return Mono.error(NO_TRANSACTION_IN_CONTEXT_EXCEPTION);
+			return Mono.error(new NoTransactionInContextException());
 		});
 	}