Fix template deduction for almost_le

[tandede]

Summary

The two-argument almost_le(x, y) overload declares three template type parameters even though only two appear in its function arguments. T3 can therefore never be deduced, so ordinary calls to this public helper fail at compile time. The neighboring almost_ge(x, y) overload already uses the intended two-parameter form.

This removes the unused T3 from only the default-precision overload. The explicit three-argument overload remains unchanged, so its caller-selected precision behavior is preserved.

Regression coverage

A new test is added to the existing ocs2_core_test_misc target. It exercises strict less-than, equality, a one-ULP approximate comparison in the reverse direction, and a clearly greater value. Keeping the test while reverting the production change makes all four calls fail to compile with couldn't infer template argument 'T3'; with the fix, the test compiles and all four assertions pass.

Validation

• Built and ran the new GoogleTest: 1 test, 4 assertions passed
• Apple clang-format 21 dry-run on testNumerics.cpp
• git diff --check

The local macOS environment does not provide the ROS 1/catkin toolchain needed for the complete project build, so the repository's Ubuntu CI will provide the full integration check.

Fixes #72.