Make site icon px size bold same as header px size

[karmatosed]

This is a small change but one that helps with consistency.

For headers you have the following:

However, note the lack of bolding for site icon px size:

There could also be a potential argument for unifying the italics too, but for at least fixing the bold would be a good start.

[karmatosed]

Noting it could also be good to change the use of px/pixel and that inconsistency at the same time in one patch.

[melchoyce]

Seems like an easy change that makes sense.

[karmatosed]

Adding bolding of pixel size and changing to say pixels not px

[melchoyce]

In 35892:

Customizer: Bold pixel value under Site Icon to match the Custom Header instructions.

Props karmatosed.
Fixes #35039.

[swissspidy]

Is the HTML tag ok in this case or should a %s placeholder be used instead?

[SergeyBiryukov]

In 35923:

I18N: Remove <strong> tags from translatable strings in WP_Customize_Manager::register_controls() and WP_Customize_Header_Image_Control::render_content().

Add translator comments.

See #35039.