CI: remove node-template from build-linux-substrate-simnet job

[alvicsam]

Removed building substrate-node-template.tar.gz in build-linux-substrate-simnet since it's not required to build temporary docker image and it caused pipeline failures

[bkchr]

The code is still there?

[alvicsam]

Sure, I only removed building it as an artifact in job related to simnet quick tests

[bkchr]

I'm confused, the title says "remove ...", but you only add code? xD

[alvicsam]

Fixed the title :)

Explanation about added lines:
There are 2 tasks: build-linux-substrate and build-linux-substrate-simnet.
build-linux-substrate runs only on master branch or when a tag is assigned. It builds substrate and runs node-template.

build-linux-substrate-simnet was added in #9959 and used build-linux-substrate as a template (including script part). Since this step is needed only to create a substrate binary which will be injected to a docker image for quick simnet tests I removed steps related to node-template. In order to do that I needed to override script section.

[bkchr]

Ty for the explanation! Now it makes sense! :)