[version] bump version to 0.10.21 (#12132)

CHANGELOG.md

llama-index-cli/pyproject.toml

llama-index-core/llama_index/core/__init__.py

llama-index-core/pyproject.toml

...s/embeddings/llama-index-embeddings-gemini/pyproject.toml

...s/embeddings/llama-index-embeddings-google/pyproject.toml

...-integrations/llms/llama-index-llms-gemini/pyproject.toml

...ex-integrations/llms/llama-index-llms-palm/pyproject.toml

...l_llms/llama-index-multi-modal-llms-gemini/pyproject.toml

...tions/readers/llama-index-readers-telegram/pyproject.toml

...or_stores/llama-index-vector-stores-google/pyproject.toml

poetry.lock

pyproject.toml