Update build

* Update Go to 1.20.
* Update golanci-lint.
* Bump modules.
* Update CI orb.
* Fix up use of deprecated ioutil.

Signed-off-by: SuperQ <superq@gmail.com>

.github/workflows/golangci-lint.yml

@@ -18,13 +18,13 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v3
       - name: install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
-          go-version: 1.18.x
+          go-version: 1.20.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'
       - name: Lint
-        uses: golangci/golangci-lint-action@v3.2.0
+        uses: golangci/golangci-lint-action@v3.4.0
         with:
-          version: v1.45.2
+          version: v1.51.2