Revert "Dockerfile: update Renode to 1.15.1"

This reverts commit de6da0b in order to
ensure that the v0.26-branch remains compatible with Zephyr 3.7 LTS.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

Dockerfile.ci

@@ -11,7 +11,7 @@ ARG CCACHE_VERSION=4.9.1
 ENV CCACHE_VERSION=$CCACHE_VERSION
 ARG DOXYGEN_VERSION=1.9.4
 ENV DOXYGEN_VERSION=$DOXYGEN_VERSION
-ARG RENODE_VERSION=1.15.1
+ARG RENODE_VERSION=1.14.0
 ENV RENODE_VERSION=$RENODE_VERSION
 ARG LLVM_VERSION=16
 ENV LLVM_VERSION=$LLVM_VERSION