Update keras requirement from ~=2.6.0 to ~=2.11.0

[dependabot[bot]]

Updates the requirements on keras to permit the latest version.

Release notes

Sourced from keras's releases.

Keras Release 2.11.0

Please see the release history at https://github.com/tensorflow/tensorflow/releases/tag/v2.11.0 for more details.

Full Changelog: https://github.com/keras-team/keras/compare/v2.10.0...v2.11.0

Commits

• e6784e4 Merge pull request #17225 from lgeiger:fix-mixed-precision-ema (#17226)
• 7411db0 Cherrypick for cl/482011499: Throw error on deprecated fields. (#17179)
• b12b9a1 Cherrypick 2 more changes for the optimizer docstring fix. (#17165)
• 1b83c91 Cherrypick all the fixes since last branch cut to r2.11. (#17160)
• 6f105ef Add a backup urls for zlib binary. (#17153)
• 5bb8d91 Merge pull request #17068 from shanejohnpaul:master
• 2c0737a Merge pull request #17119 from boneyag:include-dict-comprehension
• f5cbb0e Improve docstring for split_dataset.
• af1408d Make default Layer.get_config() automatically work for a wide range of laye...
• 8f51bd0 Fix optimizer loading when the Keras has not been imported.
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)