Change CRT to be optional dependency (#3229)

Author: zoewangg

services/s3/pom.xml

@@ -79,7 +79,8 @@
             <groupId>software.amazon.awssdk.crt</groupId>
             <artifactId>aws-crt</artifactId>
             <version>${awscrt.version}</version>
-            <scope>provided</scope>
+            <!-- Only required for certain features such as S3 CRT client -->
+            <optional>true</optional>
         </dependency>
         <!-- Test Dependencies -->
         <dependency>