[dwds] Prepare to publish 27.1.1

[nshahan]

Roll version number forward in preparation to publish.

[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:dwds	27.1.1	ready to publish	dwds-v27.1.1
package:frontend_server_client	4.0.1-wip	WIP (no publish necessary)
package:webdev	3.9.0-wip	WIP (no publish necessary)

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[nshahan]

I'm publishing this version so we can roll it into Flutter and fix the deserialization errors appearing while running web apps.