ci: bump to go 1.20 (#375)

* Update CI Go version to 1.20/1.19
* Update `golangci-lint` to v1.51.2
* Update coverage collection to use new Go 1.20 tools
* Update coverage job to only run on latest Go version

Fixes #367

.github/workflows/ci.yml

@@ -15,6 +15,7 @@ jobs:
   required:
     needs:
       - test
+      - coverage
       - lint
     runs-on: ubuntu-latest
     steps:
@@ -22,7 +23,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.18.x, 1.19.x]
+        go-version: [1.19.x, 1.20.x]
     runs-on: ubuntu-latest
     steps:
       - name: Install Go
@@ -40,6 +41,22 @@ jobs:
         run: go build ./...
       - name: Test
         run: go test -bench . ./...
+  coverage:
+    needs:
+      - test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@c4a742cab115ed795e34d4513e2cf7d472deb55f # v3.3.1
+        with:
+          go-version: 1.20.x
+          check-latest: true
+      - name: Checkout code
+        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
+        with:
+          persist-credentials: false
+      - name: Bootstrap
+        run: ./script/bootstrap
       - name: Coverage
         run: ./script/coverage
       - name: Upload Unit Test Coverage
@@ -60,7 +77,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@c4a742cab115ed795e34d4513e2cf7d472deb55f # v3.3.1
         with:
-          go-version: 1.19.x
+          go-version: 1.20.x
           check-latest: true
       - name: Checkout code
         uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0