By default, not that I'm aware of. And even if you could disable streaming by setting, one could then reverse that with the same approach
I'm not a developer, so I can't comment on how involved it would be, with OBS Studio being FOSS, for you to fork the code and add/remove/disable features as you desire (and then support that fork).
How involved that would be depends on level of security required. For example, a steering wheel lock does nothing to slow a determined, knowledgeable thief. Similarly, disabling the "Start Streaming" button would frustrate novices, but anyone familiar with any number of plugins or command-line API calls, could possibly bypass that (depends on a long list of other security measures in place).
And removing the built-in Stream target is even less useful, as streaming tends to be fairly standardized, and you can always enter in IP address or URL (easy to look up), protocol and port, etc. Removing the built-in list of streaming platforms (targets) would only slow down the ignorant/clueless. Every streaming platform I'm aware of has a dedicated web page with the exact streaming details needed (which can be manually entered into OBS Studio). Disabling in the entire Settings > Streaming section would slow down many, but one could still directly enter the info into appropriate config file(s). Meaning if you are serious, you need to remove/disable the Streaming Output code itself, then restrict write access to the program files
With that said, if you are in a security environment that requires no streaming, then rely on a 'trust me' scenario would be near pointless. You can disable outbound networking streaming protocols/ports using Group Policy on NIC, ACLS on network switch and firewall/routers (which would be WAY more secure).