Install SWIG on macOS and Windows CI for ign-math

[chapulina]

Our scripting interfaces aren't being tested on macOS and Windows. We should make sure they work and are tested.

For macOS, see this comment from @scpeters : gazebosim/gz-math#236 (comment)

[scpeters]

testing ign-math6 with swig using a custom release-tools branch:

• https://build.osrfoundation.org/job/ignition_math-ci-ign-math6-homebrew-amd64/89/

[scpeters]

testing ign-math6 with swig using a custom release-tools branch:

• https://build.osrfoundation.org/job/ignition_math-ci-ign-math6-homebrew-amd64/89/

that build has a green badge, but none of the swig tests actually ran

The following tests FAILED:
	 50 - Angle_TEST.py (Not Run)
	 51 - Color_TEST.py (Not Run)
	 52 - GaussMarkovProcess_TEST.py (Not Run)
	 53 - Kmeans_TEST.py (Not Run)
	 54 - Line2_TEST.py (Not Run)
	 55 - Line3_TEST.py (Not Run)
	 56 - PID_TEST.py (Not Run)
	 57 - python_TEST.py (Not Run)
	 58 - Rand_TEST.py (Not Run)
	 59 - RollingMean_TEST.py (Not Run)
	 60 - SemanticVersion_TEST.py (Not Run)
	 61 - SignalStats_TEST.py (Not Run)
	 62 - Spline_TEST.py (Not Run)
	 63 - Temperature_TEST.py (Not Run)
	 64 - Triangle_TEST.py (Not Run)
	 65 - Vector2_TEST.py (Not Run)
	 66 - Vector3_TEST.py (Not Run)
	 67 - Vector3Stats_TEST.py (Not Run)
	 68 - Vector4_TEST.py (Not Run)
	 69 - Angle_TEST.rb (Failed)
	 70 - GaussMarkovProcess_TEST.rb (Failed)
	 71 - Rand_TEST.rb (Failed)
	 72 - Vector2_TEST.rb (Failed)
	 73 - Vector3_TEST.rb (Failed)
	 74 - Vector4_TEST.rb (Failed)
	 75 - ruby_TEST.rb (Failed)
Errors while running CTest

jenkins didn't notice these warnings, but they are still there:

warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option]
1 warning generated.
warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option]
1 warning generated.
warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option]
1 warning generated.

[j-rivero]

that build has a green badge, but none of the swig tests actually ran

Seems a problem using python3 instead of python to invoke

      Start 50: Angle_TEST.py
Could not find executable python3
Looked in the following places:
python3
python3
Release/python3
Release/python3
Debug/python3
Debug/python3
MinSizeRel/python3
MinSizeRel/python3
RelWithDebInfo/python3
RelWithDebInfo/python3
Deployment/python3
Deployment/python3
Development/python3
Development/python3

50: Test command:  "/Users/jenkins/workspace/ignition_math-ci-ign-math6-homebrew-amd64/ign-math/src/python/Angle_TEST.py"
50: Environment variables: 
50:  PYTHONPATH=/Users/jenkins/workspace/ignition_math-ci-ign-math6-homebrew-amd64/build/fake/install/lib/python/
50:  LD_LIBRARY_PATH=/Users/jenkins/workspace/ignition_math-ci-ign-math6-homebrew-amd64/build/fake/install/lib:
Unable to find executable: python3

Let's see if this is enough gazebosim/gz-math#239

[j-rivero]

jenkins didn't notice these warnings, but they are still there:

This is hard to solve at our end. We can upgrade warnings-ng from 9.0.1 to latest but I don't see anything related in the changelog https://github.com/jenkinsci/warnings-ng-plugin/releases