docs: clarify OpenTelemetry spans for resources and prompts #3421

Job	Run time
checks / docs	41s
checks / readme-snippets	16s
checks / test (3.12, lowest-direct, windows-latest)	2m 2s
checks / test (3.11, lowest-direct, ubuntu-latest)	1m 19s
checks / pre-commit	49s
checks / test (3.13, lowest-direct, windows-latest)	2m 1s
checks / test (3.12, locked, ubuntu-latest)	1m 38s
checks / test (3.14, locked, windows-latest)	2m 40s
checks / test (3.11, locked, ubuntu-latest)	1m 27s
checks / test (3.13, locked, ubuntu-latest)	1m 17s
checks / test (3.13, locked, windows-latest)	1m 55s
checks / test (3.14, locked, ubuntu-latest)	2m 7s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 24s
checks / test (3.11, lowest-direct, windows-latest)	2m 3s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 17s
checks / test (3.10, locked, windows-latest)	2m 13s
checks / test (3.14, lowest-direct, windows-latest)	2m 32s
checks / test (3.12, locked, windows-latest)	2m 0s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 30s
checks / test (3.10, lowest-direct, windows-latest)	1m 54s
checks / test (3.13, lowest-direct, ubuntu-latest)	1m 18s
checks / test (3.11, locked, windows-latest)	2m 7s
checks / test (3.10, locked, ubuntu-latest)	1m 19s
all-green	5s
	37m 54s

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