Remove UTC mode from tutorial workflows

[wxtim]

UTC mode is a legacy setting which isn't required any-more for tutorial workflows.

Companion of cylc/cylc-doc#769

Check List

• I have read CONTRIBUTING.md and added my name as a Code Contributor.
• Contains logically grouped changes (else tidy your branch by rebase).
• Does not contain off-topic changes (use other PRs for other changes).
• Applied any dependency changes to both setup.cfg (and conda-environment.yml if present).
• Tests are not included should be tested by the validate script.
• Changelog entry not included - very small change
• Cylc-Doc pull request opened if required at cylc/cylc-doc/pull/XXXX.
• PR raised against bug fix branch because this is a doc-fix and not a feature.

[oliver-sanders]

I think the UTC mode default is still False?

https://cylc.github.io/cylc-doc/stable/html/reference/config/global.html#global.cylc[scheduler]UTC%20mode

[wxtim]

I think the UTC mode default is still False?

https://cylc.github.io/cylc-doc/stable/html/reference/config/global.html#global.cylc[scheduler]UTC%20mode

It is, but it no longer has any effect on the cycle point time zone (Old docs) so it doesn't matter any more.