upgrade to latest dependencies

bumping knative.dev/serving e640345...6a15707:
  > 6a15707 Update net-gateway-api nightly (# 15016)
  > 8e7a61c Set e2e scripts to test Gateway API and Contour (# 14999)
  > e053fe2 Update net-istio nightly (# 15018)

Signed-off-by: Knative Automation <automation@knative.team>

go.mod

@@ -60,7 +60,7 @@ require (
 	knative.dev/eventing v0.40.1-0.20240314073754-b644dad35497
 	knative.dev/hack v0.0.0-20240313135155-b9f6bf0b323b
 	knative.dev/pkg v0.0.0-20240313155908-adefab46f5e5
-	knative.dev/serving v0.40.1-0.20240314121520-e6403458d60e
+	knative.dev/serving v0.40.1-0.20240314174059-6a15707327c8
 )
 
 require (

go.sum

@@ -1555,8 +1555,8 @@ knative.dev/networking v0.0.0-20240312031421-3594f84d0be5 h1:ckn7NhdkxmD14PBEn7y
 knative.dev/networking v0.0.0-20240312031421-3594f84d0be5/go.mod h1:iXWqixPXRe1KJGNhOuydJ+FIbnc3PetpL4kqfnCcZVk=
 knative.dev/pkg v0.0.0-20240313155908-adefab46f5e5 h1:zuVGYM92M4Up6v8ficASZMme+pkrIAFbqVGDbVyQ5E8=
 knative.dev/pkg v0.0.0-20240313155908-adefab46f5e5/go.mod h1:4BYDECEnyN4FFK5uSyFCz4Wcxww/jLx4f2FL5RwYg/I=
-knative.dev/serving v0.40.1-0.20240314121520-e6403458d60e h1:OaqQ4MXlGOhFOOTSPqCPhikwGiZGQ1UQwoBmMm3vLmI=
-knative.dev/serving v0.40.1-0.20240314121520-e6403458d60e/go.mod h1:Hap8Jqynf4haO0teCc145GK9ChRVDvtugZf/rLTRoBY=
+knative.dev/serving v0.40.1-0.20240314174059-6a15707327c8 h1:8u5rqPMgbV52tafcCiicNOur0WU/2wDOiMO/VUrSbC8=
+knative.dev/serving v0.40.1-0.20240314174059-6a15707327c8/go.mod h1:Hap8Jqynf4haO0teCc145GK9ChRVDvtugZf/rLTRoBY=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=
 rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=