Update build.sh - remove versions older than 1.18

build.sh

@@ -10,7 +10,7 @@
 
 
 # All k8s versions, starting from 1.15
-K8S_VERSIONS=$(git ls-remote --refs --tags https://github.com/kubernetes/kubernetes.git | cut -d/ -f3 | grep -e '^v1\.[0-9]\{2\}\.[0-9]\{1,2\}$' | grep -v -e  '^v1\.1[0-4]\{1\}' )
+K8S_VERSIONS=$(git ls-remote --refs --tags https://github.com/kubernetes/kubernetes.git | cut -d/ -f3 | grep -e '^v1\.[0-9]\{2\}\.[0-9]\{1,2\}$' | grep -v -e  '^v1\.1[0-8]\{1\}' )
 OPENAPI2JSONSCHEMABIN="docker run -i -v ${PWD}:/out/schemas ghcr.io/yannh/openapi2jsonschema:latest"
 
 if [ -n "${K8S_VERSION_PREFIX}" ]; then