CircleCI: Upgrade build-image to Python 3 (#5717)
CircleCI: Upgrade build-image to Python 3 (#5717)

Signed-off-by: cclauss <585dd401264c1e46d17ebec1862e5d2a9b6a6c5d@me.com>
istio/envoy,envoyproxy/envoy-wasm,lyft/envoy,dnoe/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,lyft/envoy,dnoe/envoy,istio/envoy,envoyproxy/envoy-wasm,dnoe/envoy,envoyproxy/envoy,envoyproxy/envoy,jrajahalme/envoy,envoyproxy/envoy,eklitzke/envoy,envoyproxy/envoy-wasm,istio/envoy,envoyproxy/envoy,dnoe/envoy,lizan/envoy,envoyproxy/envoy,istio/envoy,jrajahalme/envoy,envoyproxy/envoy,lyft/envoy,eklitzke/envoy,envoyproxy/envoy,eklitzke/envoy,jrajahalme/envoy,envoyproxy/envoy,lyft/envoy,eklitzke/envoy,istio/envoy,dnoe/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,lizan/envoy,envoyproxy/envoy-wasm,lyft/envoy,eklitzke/envoy,jrajahalme/envoy,lizan/envoy,lyft/envoy,jrajahalme/envoy,istio/envoy,envoyproxy/envoy,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lizan/envoy,jrajahalme/envoy,istio/envoy