refactor: modernize stream collectors to unmodifiable lists using .toList()

[Baqirrizvidev]

This pull request modernizes the stream pipeline across the S3 and SQS modules by migrating legacy .collect(Collectors.toList())\ calls to Java 16+ .toList().

Benefits:

• Improved performance and reduced allocation overhead by avoiding intermediate accumulator collection.
• Enforced list unmodifiability for safer, immutable data structures returned by internal APIs.
• Cleaned up unused \java.util.stream.Collectors\ imports.

Files Modernized:

• \S3StreamingMessageSource.java\
• \S3PathMatchingResourcePatternResolver.java\
• \InterceptorExecutionFailedException.java\
• \ListenerExecutionFailedException.java\
• \DefaultListenerContainerRegistry.java\

These are safe, lightweight, non-breaking Java code modernizations that align with clean Java practices.