Update acknowledgments

Author: janden

docs/ackn.rst

@@ -48,6 +48,8 @@ Testing, bug reports, helpful discussions, contributions:
 * Vineet Bansal - py packaging
 * Jason Kaye - Gauss-Legendre quadrature code from cppdlr
 * Julius Herb - Poisson equation tutorial in Python
+* Felix F. Zimmermann - Python dependency issues in cufinufft
+* Yuwei Sun - Available thread count fix
 
 Logo design: `Sherry Choi <http://www.sherrychoi.com>`_ with input
 from Alex Barnett and Lucy Reading-Ikkanda.