By Brad Brooks and Nathan Layne (Reuters) -A Texas legislators’ probe of the Uvalde school shooting that left 21 dead blamed “systemic failures” and poor leadership for contributing to the death toll, a report released on Sunday found. The Texas House of Representatives committee investigation marked the most exhaustive attempt so far to determine why it took more than an hour for police and other officers to confront and kill the 18-year-old gunman at Robb Elementary School on May 24. The bottom line, the report found, is that “law enforcement responders failed to adhere to their active shoot…