Migrations.md: Update the rollbackable migrations guide #3601

Job	Run time
Flowzone / Event Types (pull_request, closed)	3s
Flowzone / File list	3s
Flowzone / octoscan	10s
Flowzone / actionlint	0s
Flowzone / Clean GitHub release	0s
Flowzone / Versioned source	34s
Flowzone / Check NodeJS versions	14s
Flowzone / Process docker files	0s
Flowzone / Pre-commit hooks	0s
Flowzone / Finalize npm	16s
Flowzone / Finalize npm docs	0s
Flowzone / Is rust	9s
Flowzone / Test docker	0s
Flowzone / Is balena	0s
Flowzone / Finalize docker	0s
Flowzone / Is custom	6s
Flowzone / Is python	3s
Flowzone / Is CloudFormation	0s
Flowzone / Test npm	0s
Flowzone / Generate release notes	10s
Flowzone / Test CloudFormation	0s
Flowzone / Finalize CloudFormation	0s
Flowzone / Generate SBOM for NPM	0s
Flowzone / Finalize python	0s
Flowzone / Test python poetry	0s
Flowzone / Generate SBOM for python	0s
Flowzone / Clean custom	0s
Flowzone / Test custom	0s
Flowzone / Finalize custom	0s
Flowzone / Finalize GitHub release	6s
Flowzone / Prepare deploy message	0s
Flowzone / Test rust	0s
Flowzone / Finalize rust	0s
Flowzone / Publish balena	0s
Flowzone / All tests	0s
Flowzone / Publish rust	0s
Flowzone / Generate SBOM for cargo	0s
Flowzone / Publish custom	0s
Flowzone / Publish docker	0s
Flowzone / Publish npm	0s
Flowzone / Publish to test PyPI	0s
Flowzone / Publish website	0s
Flowzone / Always custom	0s
Flowzone / Publish Github release	0s
Flowzone / All jobs	0s
Flowzone / Auto-merge	0s
	1m 54s

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