Prepare package:webdev 3.7.1 for release

[srujzs]

Pins dwds v24.3.0.

[srujzs]

FYI @bkonyi:

  Package validation found the following 2 potential issues:
  * Your dependency on "dwds" should allow more than one version. For example:
    
    dependencies:
      dwds: ^24.3.0
    
    Constraints that are too tight will make it difficult for people to use your package
    along with other packages that also depend on "dwds".
  
  * Your dependency on "vm_service_interface" should allow more than one version. For example:
    
    dependencies:
      vm_service_interface: ^2.0.1
    
    Constraints that are too tight will make it difficult for people to use your package
    along with other packages that also depend on "vm_service_interface".
  The server may enforce additional checks.

I figure we want to keep dwds pinned, but do we want to relax the vm_service_interface pin like we did with the new DWDS version?