Remove signing key ID from publishing workflow

[atsushieno]

vanniktech plugin does not work with the existing setup that is fed both in-memory key and in-memory ID.
If signing key ID is supplied then it tries to resort to local keystore and no in-memory setup is used. Just remove key id to get signing working.

I verified it works at https://github.com/atsushieno/multiplatform-library-template-nexus-publisher/actions/runs/14993346954

[atsushieno]

correction: fed both in-memory key and signing key ID (not in-memory ID).

[pahill]

Hi @atsushieno - I'll have a look at this next week, thanks for your patience. The weeks up to KotlinConf have been intense. Thanks for understanding!

[atsushieno]

totally, I was there too! Take your time.

[pahill]

@atsushieno - what is your evidence that vanniktech plugin is using the local keystore and not the in-memory setup? Please attach logs / traces. Thank you!

[atsushieno]

This is the record of build failure without the change: https://github.com/atsushieno/multiplatform-library-template-nexus-publisher/actions/runs/14990100091/job/42111980379

It comes with the build log, in case it matters.

Regarding the changes that broke publication, it seems it was brought by this change: 3529622#diff-28802fbf11c83a2eee09623fb192785e7ca92a3f40602a517c011b947a1822d3

In particular, deploy.yml that used to "import GPG key" was replaced by publish.yml without the importer.

It is indeed unnecessary because now we have the armored GPG_KEY_CONTENTS directly.

I'm not the vanniktech developer and have no idea about its implementation details. But I'm sure it won't work without importing keys as local files. And I don't think we need that step as I proved it builds and publishes.