chore: upstream dfinity/icp-js-core moved to v6.1.0

[pr-automation-bot-public]

dfinity/icp-js-core has moved past the ref the docs are verified against.

Pinned in .sources/upstream.json	v5.4.0
Latest release	v6.1.0
Compare	dfinity/icp-js-core@v5.4.0...v6.1.0
Published reference	https://js.icp.build/core/

What to re-check

@icp-sdk/core APIs in JavaScript and TypeScript code blocks: agents, identity, Candid, and the canister-env helpers. Tags match the published npm versions.

CHANGELOG.md

8 line(s) added, 0 removed.

New sections:

• ## v6.1.0 (2026-08-03)
• ## v6.0.0 (2026-07-06)
• ### Feat
• ### Feat

Full diff:

diff <(curl -sL https://raw.githubusercontent.com/dfinity/icp-js-core/v5.4.0/CHANGELOG.md) \
     <(curl -sL https://raw.githubusercontent.com/dfinity/icp-js-core/v6.1.0/CHANGELOG.md)

How to close this

1. Review the changes above against the pages named under "What to re-check".
2. Update those pages if anything they state has changed.
3. Set pinned to v6.1.0 in .sources/upstream.json in the same PR.

If nothing in the docs is affected, bump the pin on its own and say so in the PR.

Procedure: .agents/upstream-tracking.md

[marc0olo]

Done in #370. A major bump with no doc impact: v6.0.0 and v6.1.0 change Agent.readState, the delegation permissions field, effective subnet ID and URL path handling. Our examples import agent, agent/canister-env, principal, identity and candid only, never construct a Delegation and never call readState. Pin moved to v6.1.0.