[New Release]: I had 0.2.5 but on upgrading it shows 0.2.16

### What happened?

Previously I had the A2A-SDK version 0.2.5; now when I upgrade that using this command, pip install a2a-sdk --updrade then it installs version 0.2.16. 
But in the new release, it shows the latest version is 0.2.6.
I also tried uninstalling and then reinstalling, but it's still the same.

### Relevant log output

```shell

```

### Code of Conduct

- [x] #898