docs(task-graph): fix TaskOutputTabularRepository README examples for new constructor signature

[sroussey]

Summary

• Commit c011234 removed the LegacyTaskOutputRepositoryOptions shim, so TaskOutputTabularRepository's constructor now only accepts { storage: ITaskOutputStorage, outputCompression? }. Two READMEs still showed the old { tabularRepository: ... } form, which would no longer compile when users copy-paste them.
• Replaced the eight stale TaskOutputTabularRepository constructor calls across packages/task-graph/README.md and packages/task-graph/src/storage/README.md with the new shape: storage: tabularTaskOutputStorage(<raw tabular storage>). The helper tabularTaskOutputStorage is already exported from @workglow/task-graph (via src/storage/TabularTaskOutputStorage.ts re-exported by src/common.ts).
• Pulled tabularTaskOutputStorage into each example's @workglow/task-graph import block. Left every TaskGraphTabularRepository constructor untouched — that class still takes tabularRepository:.

Verification

# Every remaining `tabularRepository:` hit lives inside a `new TaskGraphTabularRepository({ ... })` block; zero inside TaskOutputTabularRepository.
grep -nB1 "tabularRepository:" packages/task-graph/README.md packages/task-graph/src/storage/README.md

# Confirms the helper is on the public surface.
grep -n "tabularTaskOutputStorage" packages/task-graph/src/common.ts packages/task-graph/src/storage/TabularTaskOutputStorage.ts

Test plan

• grep -nB1 "tabularRepository:" packages/task-graph/README.md packages/task-graph/src/storage/README.md — every hit is preceded by new TaskGraphTabularRepository({.
• Skim each touched code block in the rendered Markdown to confirm imports and constructor calls match.
• Optional: copy one of the updated examples into a scratch TS file under packages/task-graph and confirm it type-checks against the current TaskOutputTabularRepository signature.

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