Fix permission on kafka-scripts

[see-quick]

It seems that during GHA migration when downloading kafka-binaries we do not execute permissions are lost as in GHA we did split across jobs (in Azure there is just one job). This change should fix it.

The problem was spotten in test-container build where most of the tests failed with:

2026-01-28 09:29:38 ERROR [1:544] Log output from the failed container:
/testcontainers_start.sh: line 2: bin/kafka-storage.sh: Permission denied
/testcontainers_start.sh: line 3: bin/kafka-server-start.sh: Permission denied

[scholzj]

@see-quick This seems prett strange solution. Why is this needed only in GitHub Actions and not in local builds etc.?

[see-quick]

@see-quick This seems prett strange solution. Why is this needed only in GitHub Actions and not in local builds etc.?

It appears that when you upload or download an artefact using GHA, the +x permissions are excluded. At least that's what I have got from [1]. I am double-checking the builded artifacts from this PR, but the internet is somehow veeery slow as ... :/

[1] - actions/upload-artifact#38

[scholzj]

@see-quick Ahh. Makes sense. Thanks.