fix(cache-control): emit standard max-age Cache-Control directive (#4118)

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

test/e2e/conformance/tests/go-wasm-cache-control.go

@@ -49,7 +49,7 @@ var WasmPluginCacheControl = suite.ConformanceTest{
 					ExpectedResponse: http.Response{
 						StatusCode: 200,
 						Headers: map[string]string{
-							"Cache-Control": "maxAge=3600",
+							"Cache-Control": "max-age=3600",
 						},
 					},
 				},

test/e2e/conformance/tests/go-wasm-cache-control.yaml

@@ -45,4 +45,4 @@ spec:
       configDisable: false
       ingress:
         - higress-conformance-infra/wasmplugin-cache-control
-  url: oci://higress-registry.cn-hangzhou.cr.aliyuncs.com/plugins/cache-control:2.0.0
+  url: file:///opt/plugins/wasm-go/extensions/cache-control/plugin.wasm