atlasaction: add amount input to migrate apply #1490

Job	Run time
shim	14s
golangci-lint	3m 4s
schema-test	19s
shim-e2e	5s
unit-tests	1m 31s
migrate-down	11s
migrate-test	18s
monitoring	46s
schema-plan	8s
schema-apply (lint-review)	8s
schema-apply (on-the-fly, true)	15s
schema-plan-approve	0s
schema-push	7s
schema-apply (remote-repo, atlas://atlas-action/plans/20240910183610, atlas://atlas-action?tag=e2e)	16s
schema-apply (local-plan, file://20240910173744.plan.hcl)	31s
schema-apply (multiple-envs, file://20240910173744.plan.hcl)	7s
schema-apply (legacy, v0.27.0, true)	9s
	8m 9s

Provide feedback