Implement sccache and cargo registry & git sources cache in the workflows

[ggonzalez94]

templates

• Generic Runtime Template
• Evm Template

What is the feature you would like to see?

Build times are known to be long in Polkadot and our workflows already take > 1hr each.
We can improve this if we use caching(especially sccache). This is a common practice across ecosystem projects(check frontier and moonbeam for example).
This should look something like this:

 - name: Cache cargo registry & git sources
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/
            ~/.cargo/git/db/
          key: ${{ runner.os }}-cargo-unittest-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-unittest-${{ hashFiles('**/Cargo.lock') }}
            ${{ runner.os }}-cargo-unittest-
            ${{ runner.os }}-cargo-

  - name: Run sccache
    uses: mozilla-actions/[email protected]

Contribution Guidelines

• I agree to follow this project's Contribution Guidelines

[ggonzalez94]

Started working on this and the results look good so far. After adding it to the generic template the time for the workflow went from 55min on the first run to 31min the second time