remove closed source foxglove-studio from list

[pdragy]

Description

Foxglove studio tool listed in index.html (https://foxglove.dev/studio) is no longer open source, and shouldn't be included in this list of "open-source" tools as the README states. Although a trial version is available of studio, Foxglove is a trademark of Foxglove technologies inc, and both the web version and desktop app are closed source and for-profit. See relevant PR below.

Alternatively, maybe it's better to change the link to the public archived foxglove-studio repository, an older web version of foxglove-studio which is as of today is still publicly available and github and carries the MPL License.

https://github.com/foxglove/studio/pull/7534