chore: update CSI driver version to 1.15

Author: TerryHowe

prow.sh

@@ -199,7 +199,7 @@ kindest/node:v1.18.20@sha256:738cdc23ed4be6cc0b7ea277a2ebcc454c8373d7d8fb991a7fc
 # If the deployment script is called with CSI_PROW_TEST_DRIVER=<file name> as
 # environment variable, then it must write a suitable test driver configuration
 # into that file in addition to installing the driver.
-configvar CSI_PROW_DRIVER_VERSION "v1.12.0" "CSI driver version"
+configvar CSI_PROW_DRIVER_VERSION "v1.15.0" "CSI driver version"
 configvar CSI_PROW_DRIVER_REPO https://github.com/kubernetes-csi/csi-driver-host-path "CSI driver repo"
 configvar CSI_PROW_DEPLOYMENT "" "deployment"
 configvar CSI_PROW_DEPLOYMENT_SUFFIX "" "additional suffix in kubernetes-x.yy[suffix].yaml files"