Update actions/checkout digest to 9b4c13b

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	digest	1d96c77 -> 9b4c13b

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[yegor256]

@rultor please, try to merge, since 3 checks have passed

[rultor]

@rultor please, try to merge, since 3 checks have passed

@yegor256 OK, I'll try to merge now. You can check the progress of the merge here

[rultor]

@rultor please, try to merge, since 3 checks have passed

@yegor256 Done! FYI, the full log is here (took me 9min)