lint: Report all lint errors instead of early exit

[maflcko]

all-lint.py currently collects all failures. However, the 06_script.sh does not, since July this year (#28103 (comment)).

Fix this by printing all failures before exiting.

Can be tested by modifying (for example) two subtrees in the same commit and then running the linters.

[DrahtBot]

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Type	Reviewers
ACK	TheCharlatan, kevkevinpal

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[TheCharlatan]

lgtm ACK fa01f88

I checked that the CI can now correctly report multiple lint failures.

[kevkevinpal]

ACK fa01f88

tested on my own fork and saw multiple lint errors
https://github.com/kevkevinpal/bitcoin/pull/9/checks?check_run_id=18865861937

[maflcko]

tested on my own fork and saw multiple lint errors

Yeah, I guess linters should enforce their rules globally, instead of only on the diff. Otherwise, one gets different results, depending on how the diff is calculated.

Though, this is unrelated to this pull request and can be improved in the future, if there is need and interest.