Remove top navigation bottom border

[FK78]

NB - this issue exists within Psammead, not Simorgh

Simorgh PR - #7305
Psammead PR - BBC-archive/psammead#3628 ✅
Version bump PR - BBC-archive/psammead#3629 ✅

Describe the bug
There is a 1px pink line below the seconday nav bar that needs to be removed. It wasn’t intended design but a technical limitation - the way the component was built to allow the items in the nav wrapping over two lines meant that the line couldn’t stretch over 1280px.

We also have an additonal px of padding below the hover state of the News nav bar.

This impacts all page types.

This issue might be related to this #5864

To Reproduce
Steps to reproduce the behaviour:

1. Go to any Simorgh page
2. See issues mentioned above.

Expected behaviour
There should be no padding between the hover state on the News nav bar and the pink line below the secondary nav should be removed.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Testing notes

• This bug fix is expected to need manual testing.

Additional context
If picked up by ws-stories or ws-media speak to ws-home for more context as they built this component.
Denis Hernandez worked on the nav so may be good to consult with him when picking this up.

[DenisHdz]

For context, this is not a line, but a border-bottom we apply to each list item in the navigation, so when the navigation breaks into different lines, they have a separator in between:

The colour used is C_POSTBOX with 30% of transparency https://github.com/bbc/psammead/blob/latest/packages/components/psammead-navigation/src/index.jsx#L30