chrome: make tabs.discard arguments optional (#35223)
chrome: make tabs.discard arguments optional (#35223)

These arguments are both optional, see: https://developer.chrome.com/extensions/tabs#method-discard
georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped