[Chore] FIx tests querying OpenShift user workload monitoring stack

[IshwarKanse]

In OpenShift 4.16 tokens for service account are not generated by default and we have to now use the TokenRequest API to create token. The PR fixes the check_metrics.sh script to create a token from prometheus-user-workload SA. Tested on OpenShift 4.16 and 4.15

--- PASS: chainsaw (1680.86s)
    --- PASS: chainsaw/ossm-monolithic-otel (455.74s)
    --- PASS: chainsaw/ossm-tempostack (368.49s)
    --- PASS: chainsaw/ossm-tempostack-otel (404.15s)
    --- PASS: chainsaw/monitoring (215.61s)
    --- PASS: chainsaw/red-metrics (236.87s)
    --- PASS: chainsaw/route (51.14s)
    --- PASS: chainsaw/gateway (68.05s)
    --- PASS: chainsaw/monolithic-multitenancy-openshift (115.89s)
    --- PASS: chainsaw/monolithic-memory (116.76s)
    --- PASS: chainsaw/monolithic-pv (120.70s)
    --- PASS: chainsaw/monolithic-s3-tls (128.72s)
    --- PASS: chainsaw/reconcile (148.41s)
    --- PASS: chainsaw/receivers-tls (166.55s)
    --- PASS: chainsaw/generate (80.47s)
    --- PASS: chainsaw/custom-ca (163.19s)
    --- PASS: chainsaw/monolithic-route (94.97s)
    --- PASS: chainsaw/compatibility (179.55s)
    --- PASS: chainsaw/monolithic-ingestion-mtls (135.85s)
    --- PASS: chainsaw/tempo-single-tenant-auth (180.16s)
    --- PASS: chainsaw/receivers-mtls (183.40s)
    --- PASS: chainsaw/monolithic-single-tenant-auth (116.72s)
    --- PASS: chainsaw/monolithic-multitenancy-static (113.36s)
    --- PASS: chainsaw/multitenancy (181.94s)
PASS
Tests Summary...
- Passed  tests 23
- Failed  tests 0
- Skipped tests 0
Done.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 76.41%. Comparing base (63a06ca) to head (1fee59f).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #940 +/- ## ======================================= Coverage 76.41% 76.41% ======================================= Files 94 94 Lines 6071 6071 ======================================= Hits 4639 4639 Misses 1160 1160 Partials 272 272 ``` | [Flag](https://app.codecov.io/gh/grafana/tempo-operator/pull/940/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=grafana) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/grafana/tempo-operator/pull/940/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=grafana) | `76.41% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=grafana#carryforward-flags-in-the-pull-request-comment) to find out more.

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