Update dependency cffsubr to v0.3.0

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
cffsubr	==0.2.9.post1 -> ==0.3.0

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Release Notes

adobe-type-tools/cffsubr (cffsubr)

### [`v0.3.0`](https://togithub.com/adobe-type-tools/cffsubr/releases/tag/v0.3.0) [Compare Source](https://togithub.com/adobe-type-tools/cffsubr/compare/v0.2.9.post1...v0.3.0) Updated embedded `tx` to latest afdko version v4.0.1 https://github.com/adobe-type-tools/afdko/releases/tag/4.0.1

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Configuration

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