tests: remove unnecessary declaration and fix typo #3546

Job	Run time
prepare	5s
binaries (darwin/amd64)	1m 20s
binaries (darwin/arm64)	1m 4s
binaries (linux/amd64)	2m 5s
binaries (linux/arm/v7)	2m 8s
binaries (linux/arm64)	2m 7s
binaries (linux/s390x)	1m 58s
binaries (linux/ppc64le)	2m 10s
binaries (linux/riscv64)	2m 29s
binaries (windows/amd64)	1m 35s
binaries (windows/arm64)	1m 43s
test / prepare	1m 46s
test / run (containerd, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, integration)	7m 32s
test / run (containerd-rootless, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, integr...	8m 45s
test / run (containerd-1.6, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, integration)	7m 23s
test / run (containerd-snapshotter-stargz, ./client ./cmd/buildctl ./worker/containerd ./solver ./fronte...	8m 26s
test / run (oci, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, integration)	5m 15s
test / run (oci-rootless, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, integration)	5m 3s
test / run (oci-rootless-slirp4netns-detachnetns, ./client ./cmd/buildctl ./worker/containerd ./solver ....	5m 5s
test / run (oci-snapshotter-stargz, ./client ./cmd/buildctl ./worker/containerd ./solver ./frontend, int...	5m 11s
test / run (./..., 1, integration gateway)	4m 36s
test / run (./client, containerd, nydus, integration)	7m 26s
test / run (./client, oci, nydus, integration)	5m 18s
test / run (./..., nydus, 1, integration)	4m 25s
image	8m 51s
image (rootless)	9m 14s
release	5s
	1h 53m 5s

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