chore(ci): start saving/restoring go build cache (#721)

This commit uses a build cache for the coverage and netxlite github actions.

See https://github.com/ooni/probe/issues/2093.

.github/workflows/checks.yml

@@ -1,4 +1,4 @@
-# checks performs several code quality checks
+# performs several code quality checks
 name: checks
 on:
   pull_request:
@@ -6,7 +6,7 @@ on:
     branches:
       - "master"
 jobs:
-  test:
+  perform_code_quality_checks:
     runs-on: "${{ matrix.os }}"
     strategy:
       matrix:

.github/workflows/coverage.yml

@@ -1,4 +1,4 @@
-# coverage computes the code coverage
+# runs tests and computes the code coverage
 name: coverage
 on:
   pull_request:
@@ -7,7 +7,8 @@ on:
       - "master"
       - "release/**"
 jobs:
-  test:
+
+  measure_coverage:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
@@ -15,17 +16,19 @@ jobs:
           - "1.17.9"
           - "1.18.1"
     steps:
-      - uses: actions/setup-go@v1
+      - uses: magnetikonline/action-golang-cache@v2
         with:
           go-version: "${{ matrix.go }}"
+          cache-key-suffix: "-coverage-${{ matrix.go }}"
       - uses: actions/checkout@v2
       - run: go test -short -race -tags shaping -coverprofile=probe-cli.cov ./...
       - uses: shogo82148/actions-goveralls@v1
         with:
           path-to-profile: probe-cli.cov
           parallel: true
-  finish:
-    needs: test
+
+  finish_measuring_coverage:
+    needs: measure_coverage
     runs-on: ubuntu-latest
     steps:
       - uses: shogo82148/actions-goveralls@v1

.github/workflows/netxlite.yml

@@ -6,15 +6,16 @@ on:
     branches:
       - "master"
 jobs:
-  test:
+  test_netxlite_package:
     runs-on: "${{ matrix.os }}"
     strategy:
       matrix:
         go: [ "1.17.9" ]
         os: [ "ubuntu-20.04", "windows-2019", "macos-10.15" ]
     steps:
-      - uses: actions/setup-go@v1
+      - uses: magnetikonline/action-golang-cache@v2
         with:
           go-version: "${{ matrix.go }}"
+          cache-key-suffix: "-coverage-${{ matrix.go }}"
       - uses: actions/checkout@v2
       - run: go test -race ./internal/netxlite/...