Don't use GMT_THEME=cookbook in cookbook scripts

[seisman]

In some examples in the cookbook, we use the GMT_THEME=cookbook setting. For example:

Why do we use it? Users may be confused that why GMT_THEME=cookbook is always presented in these examples.

[joa-quim]

Agree.

[maxrjones]

It's included so that all the output images don't have different font and pen sizes due to the modern mode conf default of auto, which would look bad.

[seisman]

It's included so that all the output images don't have different font and pen sizes due to the modern mode conf default of auto, which would look bad.

I'm not fully convinced by this reason. If the images look bad due to the different font and pen sizes, we should update the scripts so that all basemaps have similar dimensions (thus similar font and pen sizes).

[maxrjones]

It's included so that all the output images don't have different font and pen sizes due to the modern mode conf default of auto, which would look bad.

I'm not fully convinced by this reason. If the images look bad due to the different font and pen sizes, we should update the scripts so that all basemaps have similar dimensions (thus similar font and pen sizes).

I recommend submitting a PR for one section of the cookbook with your solution rather than using the cookbook theme so that we can review the appearance.

[joa-quim]

Now close this?

[seisman]

there are still a lot to update

[seisman]

Closed by #8509.