[StepSecurity] ci: Harden GitHub Actions #5939

Job	Run time
Unit tests (1.22.x)	42s
Unit tests (1.23.x)	4m 2s
Integration tests	15m 12s
Colima (v0.6.5)	6m 39s
Integration tests (on Linux) (alpine.yaml)	6m 28s
Windows tests	5m 39s
Lints	1m 42s
Integration tests (on Linux) (debian.yaml)	6m 17s
Integration tests (on Linux) (fedora.yaml)	6m 19s
Integration tests (on Linux) (opensuse.yaml)	8m 55s
Upgrade test (v0.15.1)	10m 17s
Integration tests (on Linux) (experimental/net-user-v2.yaml)	7m 14s
Integration tests (on Linux) (experimental/9p.yaml)	6m 35s
VMNet test	26m 33s
Integration tests (on Linux) (docker.yaml)	7m 13s
Integration tests (on Linux) (../hack/test-templates/alpine-iso-9p-writable.yaml)	6m 3s
vz (default.yaml)	10m 19s
Integration tests (on Linux) (../hack/test-templates/test-misc.yaml)	19m 28s
vz (fedora.yaml)	9m 55s
	2h 45m 32s

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