build: disable sccache

[lklimek]

Issue being fixed or feature implemented

sccache is not stable enough

What was done?

• disabled sccache by default, can be re-enabled by setting RUSTC_WRAPPER=sccache
• updated documentation
• removed sccache from github workflows and actions
• re-enabled caching of /target
• modified Dockerfile to only install and use sccache if it's enabled
• moved installation of wasm-bindgen-cli to separate stage, to use sccache if it's enabled

How Has This Been Tested?

• locally with docker buildx build ...
• github actions

Breaking Changes

None

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[shumkov]

I just realized that if we merge it now, everything become super slow. Maybe we should wait until mount cache is ready?

[shumkov]

Closed in favor of #1167