readme: move login step up #2107

Job	Run time
bake (default)	17s
error-check	9s
error-msg	9s
bake (release)	26s
provenance	30s
source	1m 3s
sbom (image, type=image,name=localhost:5000/name/app:latest,push=true)	28s
provenance (mode=max)	15s
provenance (builder-id=foo)	28s
sbom (binary, /tmp/bake-build)	28s
provenance (false)	23s
standalone	9s
provenance (true)	14s
docker-config-malformed	11s
git-context	1m 15s
git-context-and-local	1m 27s
group	15s
load-and-push	34s
multi-output	39s
proxy-buildkitd	41s
proxy-docker-config	21s
set	30s
summary-disable	22s
allow (v0.19.0-rc2)	16s
annotations-disabled	29s
allow (v0.18.0)	20s
allow (v0.17.1)	18s
checks (latest)	25s
checks (v0.14.1)	20s
record-retention-days (2)	19s
record-retention-days (0)	24s
record-upload-disable	39s
summary-disable-deprecated	9s
summary-not-supported	11s
	15m 4s

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