rsconnect 1.6.1

• Fix account registration from RStudio. (#1250)

• SPCS/Snowflake authentication supports Connect API keys for user
  identification. The connectSPCSUser() function now requires an apiKey
  parameter, and the API key is included in the X-RSC-Authorization header
  alongside Snowflake token authentication. This aligns with updated Connect
  server requirements where Snowflake tokens provide proxied authentication
  while API keys identify users to the Connect server itself.