Use `uv sync --locked` in Dockerfile templates per official uv Docker guidance #961

Job	Run time
find-tutorials	5s
test-00_sync/000_hello_acp	1m 59s
test-00_sync/020_streaming	1m 57s
test-10_async/00_base/000_hello_acp	2m 9s
test-10_async/00_base/010_multiturn	4m 0s
test-00_sync/010_multiturn	2m 17s
test-00_sync/030_langgraph	1m 57s
test-10_async/10_temporal/010_agent_chat	2m 8s
test-10_async/00_base/100_langgraph	2m 1s
test-10_async/00_base/020_streaming	2m 4s
test-10_async/10_temporal/000_hello_acp	3m 51s
test-10_async/10_temporal/070_open_ai_agents_sdk_tools	2m 6s
test-10_async/10_temporal/050_agent_chat_guardrails	2m 4s
test-10_async/10_temporal/030_custom_activities	1m 58s
test-10_async/10_temporal/080_open_ai_agents_sdk_human_in_the_loop	3m 27s
test-10_async/10_temporal/090_claude_agents_sdk_mvp	2m 5s
test-10_async/10_temporal/060_open_ai_agents_sdk_hello_world	1m 46s
test-10_async/00_base/030_tracing	2m 49s
test-10_async/10_temporal/020_state_machine	2m 26s
test-10_async/00_base/080_batch_events	2m 9s
test-10_async/00_base/040_other_sdks	2m 0s
Test Summary	5s
	47m 23s

Provide feedback