BLD: do not fail fast on build_wheels

[tangkong]

I went and uploaded pyca_epics to test_pypi, and was able to install it from the wheel (for macos). The ubuntu/linux wheels didn't run because the build matrix was set to fail_fast=True

On my mac

(py312)roberttk@PC100147:~$ pip install pyca_epics --index-url https://test.pypi.org/simple/ --no-deps
Looking in indexes: https://test.pypi.org/simple/
Collecting pyca_epics
  Downloading https://test-files.pythonhosted.org/packages/d1/2c/1efff5c4b17e53cd339290b3f350ab6f5529fcc9f704fceceea24177ea44/pyca_epics-3.3.2-cp312-cp312-macosx_11_0_arm64.whl.metadata (3.8 kB)
Downloading https://test-files.pythonhosted.org/packages/d1/2c/1efff5c4b17e53cd339290b3f350ab6f5529fcc9f704fceceea24177ea44/pyca_epics-3.3.2-cp312-cp312-macosx_11_0_arm64.whl (698 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 698.7/698.7 kB 11.3 MB/s eta 0:00:00
Installing collected packages: pyca_epics
Successfully installed pyca_epics-3.3.2

(py312)roberttk@PC100147:~$ python -c "import pyca; print(pyca.__file__)"
/Users/roberttk/miniconda3/envs/py312/lib/python3.12/site-packages/pyca.cpython-312-darwin.so