CLEANUP/MINOR: ci: remove deprecated gitlab token usage #485

Job	Run time
HAProxy check commit message	0s
generate-models	1m 12s
generate-specification	45s
Build	21s
golangci-lint	1m 4s
go mod tidy	11s
lint-spec	7s
Tests	36s
e2e on HAProxy (2.1)	39s
e2e on HAProxy (2.2)	38s
e2e on HAProxy (2.3)	37s
e2e on HAProxy (2.4)	39s
e2e on HAProxy (2.5)	37s
e2e on HAProxy (2.6)	41s
e2e on HAProxy (2.7)	39s
e2e on HAProxy (2.8)	41s
	9m 27s

Provide feedback