Fix avro build: add pkg-config for libjansson detection

CMake couldn't find libjansson because pkg-config was missing.

Author: pyramation

Dockerfile.pg_lake

@@ -45,6 +45,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     # pg_lake dependencies
     cmake \
     ninja-build \
+    pkg-config \
     libssl-dev \
     libsnappy-dev \
     libjansson-dev \