chore: update dependency express to v5

[maemayve]

Update Express dependency to 5.0.0 and change path syntax to match new Express format.

[caugner]

@akerekes Isn't this a breaking change that should have been released in a major release, given that the signature of the http method changed? Users of the functions-framework need to migrate from express v4 to express v5 to update to functions-framework v4.0.1.

This change is not even mentioned in the changelog.

See also: #673

[Sandbye]

@akerekes Isn't this a breaking change that should have been released in a major release, given that the signature of the http method changed? Users of the functions-framework need to migrate from express v4 to express v5 to update to functions-framework v4.0.1.

This change is not even mentioned in the changelog.

See also: #673

This very much is a breaking change. I have been investigating why my deployed cloud functions was not working anymore.
Version 4.0.1 breaks my express, because of major bump.

This is still quite current (a month). And is seen as a verified and safe version. Which it is not.
This broke req.query for me, for all express calls on get methods.

Im creating an issue on this.