Fix Windows build: use bash shell for version update step

[baryhuang]

Problem

Windows build failing with:

The term 'VERSION=v0.1.45' is not recognized as a name of a cmdlet, function, script file, or executable program.

Root Cause

Windows runners use PowerShell by default, which doesn't support bash variable syntax like VERSION="${VERSION#v}".

Solution

Add shell: bash to the version update step to ensure it runs in bash on all platforms.

- name: Update version from tag
  shell: bash  # <-- Added this
  run: |
    VERSION="${{ github.ref_name }}"
    ...

Co-authored-by: openhands openhands@all-hands.dev

@baryhuang can click here to continue refining the PR