[Node SDK] Upgrades OpenAPI Generator from 7.12.0 to 7.26.0

[gbiernacki-dropbox]

Upgrades OpenAPI Generator from 7.12.0 to 7.26.0 for the Node SDK. No public API changes.

Upstream template changes

Change	Upstream PR	Version
Simplified path parameter replacement	#23485	7.22.0
Serialization falls back to the API property name when the TypeScript name isn't set	#24967	7.26.0
Non-Date values in date fields are passed through	#17514	7.26.0
JSON-serialized header parameters	#25088	7.26.0

Docs

Model docs are now generated with 7.26.0 as well (previously 7.8.0), so detectionMode is documented as string.

Release

This will ship as a minor release (1.15.0):

• No breaking changes: generated type declarations are identical, and runtime and dependency requirements are unchanged.
• Serialization now handles input that was previously dropped or rejected (API property names, non-Date values in date fields), which is new backwards-compatible behaviour.