AWS CEO Matt Garman on why he isn't worried about an AI bubble: no single customer dominates AWS capacity, and enterprises are already seeing positive ROI. "We feel really good about the spend we're making now. I get lots of questions about how you feel about that spend, and 'Are you nervous about a bubble?'" "We take a diversified approach, so not all of our capacity is bundled up in one customer." "Also, AWS is where people come to launch their production workloads. The majority of our…