Improve HTTP method label handling in prometheus metrics #11786

Job	Run time
changes	6s
test-go	4m 7s
Verify Doc generation	13s
Build	4m 9s
lua-lint	8s
Chart / Test	0s
Kubernetes (v1.32.0) / Kubernetes	53m 14s
Kubernetes (v1.29.12) / Kubernetes	46m 11s
Kubernetes (v1.30.8) / Kubernetes	48m 42s
Kubernetes chroot (v1.28.15) / Kubernetes CHROOT	52m 39s
Kubernetes (v1.31.4) / Kubernetes	45m 35s
Kubernetes (v1.28.15) / Kubernetes	45m 44s
Kubernetes chroot (v1.29.12) / Kubernetes CHROOT	47m 19s
Kubernetes chroot (v1.30.8) / Kubernetes CHROOT	46m 10s
Kubernetes chroot (v1.31.4) / Kubernetes CHROOT	45m 38s
Kubernetes chroot (v1.32.0) / Kubernetes CHROOT	50m 58s
	8h 10m 53s

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