WASM CI improvements

I looked at the definition of the wasm pipelines and it seems there are a few issues which need addressing:

• Why are the patches to process and hsc2hs not merged into the upstream repos?
• Why is the build environment provided by ghc-wasm-meta not provided statically in a docker image rather than fetched over the network? This introduces a large vector for failure which is not desirable on a pipeline which runs on every job. (See https://gitlab.haskell.org/ghc/ghc/-/jobs/1275577)
• Why is the expiration of artifacts set to 1 year, when the standard for a validate pipeline is 2 weeks.
• Why is the CI job not generated by the same standard as all other platform jobs using gen_ci.hs.
• Why is the trigger when: always, this doesn't align with how other validate/nightly/release jobs are configured. Another strong reason why these jobs need to be generated using gen_ci.hs.

Given the highly critical nature of the validate pipelines.. I am going to move the wasm pipelines into the nightly build and mark them as allowed to fail for now. When @TerrorJack returns he can pick up the task of making the pipelines robust enough to place into the normal validate workflow.