Use Case

As a maintainer, I want one macOS deployment target across the addon and the libmongocrypt build, so that our minimum supported macOS is stated once and matches what we actually ship.

User Experience

• n/a, no change to what users receive

Dependencies

• Raised by Copilot on PR #137 (NODE-7704), where the macOS build was changed to produce a universal libmongocrypt

Risks/Unknowns

• This is a consistency fix, not a behaviour change. Measured on a universal build produced locally with the PR #137 changes:
• libmongocrypt x86-64 objects carry LC_VERSION_MIN_MACOSX version 10.12, 93 objects
• libmongocrypt arm64 objects carry LC_BUILD_VERSION minos 11.0, 93 objects, because clang cannot express 10.12 for arm64 and clamps it
• the shipped addon reports minos 11.0 in both slices, since binding.gyp sets MACOSX_DEPLOYMENT_TARGET to 11
• So the effective floor is already macOS 11 and the 10.12 value is dead intent. Confirm this holds on the CI runners before treating the change as a no-op
• We do not document a minimum macOS version anywhere. README only says "MacOS universal binary". Decide whether to state the floor explicitly, and whether it belongs in the compat table
• DCMAKE_OSX_DEPLOYMENT_TARGET: '10.12' has been in .github/scripts/libmongocrypt.mjs since the repo was created, commit 7681940, so check whether anything downstream depends on the older value before raising it

Acceptance Criteria

Implementation Requirements

• Set CMAKE_OSX_DEPLOYMENT_TARGET in .github/scripts/libmongocrypt.mjs to match MACOSX_DEPLOYMENT_TARGET in binding.gyp, currently 11

Testing Requirements

• Both slices of the built addon still report minos 11.0, unchanged from today
• libmongocrypt objects report 11.0 for both architectures
• macOS jobs pass, including the x64 prebuild verification job added in NODE-7704

Documentation Requirements

• If we decide to state a minimum macOS version, add it to the README