CI gardening maintenance (#3706)

## Issue Addressed

Closes https://github.com/sigp/lighthouse/issues/3656

## Proposed Changes

* Replace `set-output` by `$GITHUB_OUTPUT` usage
* Avoid rate-limits when installing `protoc` by making authenticated requests (continuation of https://github.com/sigp/lighthouse/pull/3621)
* Upgrade all Ubuntu 18.04 usage to 22.04 (18.04 is end of life)
* Upgrade macOS-latest to explicit macOS-12 to silence warning
* Use `actions/checkout@v3` and `actions/cache@v3` to avoid deprecated NodeJS v12

## Additional Info

Can't silence the NodeJS warnings entirely due to https://github.com/sigp/lighthouse/issues/3705. Can fix that in future.

.github/workflows/local-testnet.yml

@@ -12,11 +12,11 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu-18.04
-          - macos-latest
+          - ubuntu-22.04
+          - macos-12
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v3
 
       - name: Get latest version of stable Rust
         run: rustup update stable
@@ -28,7 +28,7 @@ jobs:
         run: npm install ganache@latest --global
 
       # https://github.com/actions/cache/blob/main/examples.md#rust---cargo
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         id: cache-cargo
         with:
           path: |