Ambitious Female Main Character + No Romance

I am still thinking but the only person who springs to mind is Cordelia Gray in 'An Unsuitable Job for a Woman' and 'The Skull Beneath the Skin' by P D James. She has previous relationships hinted at in her back story so she may not be 'suitable'.

I am sure there are more so I may be able to come back to you.

You could look up
​The Steerswoman by Rosemary Kirstein...

Haven't read it.

Personally dislike programmes where having an affair with your colleague is 50% of the story line but that is liked by others who like the added drama, if you don't like it change station.

I don’t think Vera ( Anne Cleeves) has had any flings but she does have a backstory with her relationship to her father.

There are strong (and some weak) female characters in my books. Their stories are usually about themselves but mostly about them in their context of work and relationships with others there. Not advertising btw. I was just struck by the opening post. Most women just live their lives not necessarily looking for romance and with plenty of other things to contend with!

You might find "Suits Me" by Diane Middlebrook interesting.
It is a biography of Billy Tipton who was an American jazz pianist and band leader who only succeeded as a professional musician by pretending to be a man. There are references to her relationships with women but the story centres on her success in a mans' world.