[forwardport] chore: use go1.17.3 (#588) (#589)

This diff forward ports adcb0f9ae3b9e074c301d4f7f0e8f2d0ef6466b9.

Original commit message:

- - -

- ensure we use go1.17.3 in workflows

- update to a version of ooni/oohttp that uses go1.17.3

This change WILL need to be forward ported to master.

Closes https://github.com/ooni/probe/issues/1861

.github/workflows/coverage.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        go: [ "1.17.2" ]
+        go: [ "1.17.3" ]
     steps:
       - uses: actions/setup-go@v1
         with: