Bump golang from 86a3c48 to 2bd56f0 in /tests (#2644)

Bumps golang from `86a3c48` to `2bd56f0`.

---
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@sha256:86a3c48a61915a8c62c0e1d7594730399caa3feb73655dfe96c7bc17710e96cf
+FROM golang@sha256:2bd56f00ff47baf33e64eae7996b65846c7cb5e0a46e0a882ef179fd89654afa
 
 # Set the user to root
 USER root