Improve label for time value on jobs index page
## 🧩 Problem The `Timing` label on the job index page ([example](https://gitlab.com/gitlab-org/gitlab/-/jobs)) is inconsistent with `Duration` label on the pipeline index page ([example](https://gitlab.com/gitlab-org/gitlab/-/pipelines)) ## 📑 Background </details> <details><summary> On the job index page</summary> | Job Index Page | |----| | ![Screen_Shot_2021-04-07_at_5.15.12_PM](/uploads/fec6e89d48f7a321fe54ea965a2c424d/Screen_Shot_2021-04-07_at_5.15.12_PM.png) | </details> ## Proposal Change the `Timing` label to be consistent with label on pipeline index page.
issue