version bump to v0.7.4

[qingyun-wu]

Why are these changes needed?

Related issue number

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• I've included any doc changes needed for https://docs.ag2.ai/. See https://docs.ag2.ai/docs/contributor-guide/documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Flag	Coverage Δ
3.10	42.37% <100.00%> (-16.83%)	⬇️
3.11	28.31% <100.00%> (ø)
3.12	26.67% <100.00%> (-0.01%)	⬇️
3.13	42.85% <100.00%> (-0.01%)	⬇️
3.9	41.64% <100.00%> (-0.01%)	⬇️
anthropic	15.80% <100.00%> (ø)
bedrock	16.16% <100.00%> (ø)
browser-use	29.42% <100.00%> (ø)
cerebras	15.88% <100.00%> (ø)
cohere	15.93% <100.00%> (ø)
commsagent-discord	29.92% <100.00%> (ø)
commsagent-slack	29.90% <100.00%> (ø)
commsagent-telegram	29.85% <100.00%> (ø)
crawl4ai	29.62% <100.00%> (ø)
docs	28.62% <100.00%> (ø)
gemini	15.88% <100.00%> (ø)
graph-rag-falkor-db	28.08% <100.00%> (ø)
groq	15.90% <100.00%> (ø)
interop	29.48% <100.00%> (ø)
jupyter-executor	30.69% <100.00%> (ø)
lmm	18.65% <100.00%> (ø)
long-context	15.07% <100.00%> (ø)
macos-latest	43.74% <100.00%> (ø)
mistral	15.62% <100.00%> (ø)
ollama	16.28% <100.00%> (ø)
retrievechat	29.59% <100.00%> (ø)
retrievechat-mongodb	29.58% <100.00%> (ø)
retrievechat-pgvector	29.58% <100.00%> (ø)
retrievechat-qdrant	29.53% <100.00%> (ø)
teachable	15.24% <100.00%> (ø)
together	15.93% <100.00%> (ø)
twilio	28.30% <100.00%> (ø)
ubuntu-latest	42.98% <100.00%> (-16.64%)	⬇️
websurfer	18.07% <100.00%> (ø)
windows-latest	41.61% <100.00%> (-15.74%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
autogen/version.py	100.00% <100.00%> (ø)

... and 47 files with indirect coverage changes

[LeoLjl]

LGTM