Single Detail Panel: Tab titles do not need bold font weight

[jo-oikawa]

Current:

Uses '--vscode-agents-fontWeight-semiBold'

Expected:

[lszomoru]

@jo-oikawa, this seems to be consistent with the font weight in the editor window tabs. Do we need to fix it in both windows?

[jmoses]

Unsolicited opinion: yes, the bold tabs are distracting. I keep expected the bold to mean something (eg: content changed).