Replace yq with sed (#2062)

Problem: yq is not installed by default in all systems

Solution: Replace it with sed, which is more popular

Author: lucacome

tests/Makefile

@@ -4,13 +4,13 @@ CONFORMANCE_TAG = latest## Tag for the conformance test runner image
 GATEWAY_CLASS = nginx## Gateway class to use
 GINKGO_FLAGS =
 GINKGO_LABEL =
-GW_API_VERSION ?= $(shell yq eval '.resources[0] | split("ref=v") | .[1]' ../config/crd/gateway-api/standard/kustomization.yaml)## Supported Gateway API version from current NGF
+GW_API_VERSION ?= $(shell sed -n 's/.*ref=v\(.*\)/\1/p' ../config/crd/gateway-api/standard/kustomization.yaml)## Supported Gateway API version from current NGF
 GW_API_PREV_VERSION ?= 1.0.0## Supported Gateway API version from previous NGF release
-GW_SERVICE_TYPE=NodePort## Service type to use for the gateway
-GW_SVC_GKE_INTERNAL=false
+GW_SERVICE_TYPE = NodePort## Service type to use for the gateway
+GW_SVC_GKE_INTERNAL = false
 K8S_VERSION ?= latest## Kubernetes version to use. Expected format: 1.24 (major.minor) or latest
 NGF_VERSION ?= $(shell git describe --tags $(shell git rev-list --tags --max-count=1))## NGF version to be tested (defaults to latest tag)
-PULL_POLICY=Never## Pull policy for the images
+PULL_POLICY = Never## Pull policy for the images
 PROVISIONER_MANIFEST = conformance/provisioner/provisioner.yaml
 SUPPORTED_FEATURES = HTTPRouteQueryParamMatching,HTTPRouteMethodMatching,HTTPRoutePortRedirect,HTTPRouteSchemeRedirect,HTTPRouteHostRewrite,HTTPRoutePathRewrite,GatewayPort8080,HTTPRouteResponseHeaderModification,GRPCExactMethodMatching,GRPCRouteListenerHostnameMatching,GRPCRouteHeaderMatching