Bump keras from 3.3.3 to 3.4.0 (#1150)

Bumps [keras](https://github.com/keras-team/keras) from 3.3.3 to 3.4.0.
- [Release notes](https://github.com/keras-team/keras/releases)
- [Commits](keras-team/keras@v3.3.3...v3.4.0)

---
updated-dependencies:
- dependency-name: keras
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

demos/imagetagger/requirements.txt

@@ -1,6 +1,6 @@
 aiohttp==3.8.6
 aiohttp-jinja2==1.5.1
-keras==3.3.3
+keras==3.4.0
 Pillow==10.3.0
 tensorflow==2.16.1
 trafaret_config==2.0.2