Update extensions.json (#835)

* Update extensions.json

cancel deprecation of CSS Peek extension:
EclipseFdn/open-vsx.org#3540

* Remove `pranaygp.vscode-css-peek`

---------

Co-authored-by: Filip Troníček <filip@gitpod.io>

Author: tfroment

extension-control/extensions.json

@@ -297,7 +297,6 @@
         },
         "iocave.customize-ui": true,
         "iocave.monkey-patch": true,
-        "pranaygp.vscode-css-peek": true,
         "redhat.vscode-wsdl2rest": true,
         "ms-vscode.node-debug2": true,
         "ms-vscode.node-debug": true,