Bump golang from 8144f2d to ef61a20 in /tests (#2463)

Bumps golang from `8144f2d` to `ef61a20`.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

tests/Dockerfile

@@ -1,5 +1,5 @@
 # The Dockerfile's resulting image is purpose-built for executing Jaeger Operator e2e tests within the OpenShift release (https://github.com/openshift/release) using Prow CI.
-FROM golang@sha256:8144f2d44d2262fa930b437200fc4ada624d8a0b9c83d688e2a6f545d097c45b
+FROM golang@sha256:ef61a20960397f4d44b0e729298bf02327ca94f1519239ddc6d91689615b1367
 
 # Set the user to root
 USER root