Upgrade WEB_VAULT_VERSION to Version v2.26.1

[BrutalBirdie]

https://git.cloudron.io/cloudron/vaultwarden-app/-/blob/master/Dockerfile#L16

https://github.com/dani-garcia/bw_web_builds/releases

Why? Because :

Unhide the API Key section under My Account

Which is missing in the current version.

[girish]

@BrutalBirdie Usually, there is a backend release along with a front end release. It looks like it was updated here - https://github.com/dani-garcia/vaultwarden/commit/06f8e69c7026d4aacc15bbbe0a87377e131336db .

We have to ask @nebulon if it's safe to upgrade frontend without backend release.

[nebulon]

I have update the package, the web versions seems to be compatible with the backend.