README.md: Fix Ubuntu package list (#5679)
README.md: Fix Ubuntu package list (#5679)

- `realpath` is now in `coreutils`.

Signed-off-by: Per Lundberg <71d64ded6fa579d17550ad9d286fc776c741ceaa@gmail.com>
istio/envoy,envoyproxy/envoy,lizan/envoy,dnoe/envoy,eklitzke/envoy,dnoe/envoy,lizan/envoy,lizan/envoy,envoyproxy/envoy,lizan/envoy,dnoe/envoy,istio/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,istio/envoy,envoyproxy/envoy-wasm,lyft/envoy,istio/envoy,jrajahalme/envoy,envoyproxy/envoy,lyft/envoy,eklitzke/envoy,lyft/envoy,envoyproxy/envoy,istio/envoy,lyft/envoy,eklitzke/envoy,envoyproxy/envoy,jrajahalme/envoy,envoyproxy/envoy-wasm,dnoe/envoy,eklitzke/envoy,envoyproxy/envoy-wasm,lizan/envoy,jrajahalme/envoy,envoyproxy/envoy-wasm,jrajahalme/envoy,jrajahalme/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lizan/envoy,envoyproxy/envoy,dnoe/envoy,lyft/envoy,envoyproxy/envoy,istio/envoy,lyft/envoy,istio/envoy,envoyproxy/envoy-wasm,jrajahalme/envoy,eklitzke/envoy,envoyproxy/envoy,eklitzke/envoy