ci: fix broken sdist/wheel build step in deploy workflow - #22

  4 files  ±0    4 suites  ±0   1m 49s ⏱️ -5s
 32 tests ±0   31 ✅ ±0  1 💤 ±0  0 ❌ ±0 
108 runs  ±0  106 ✅ ±0  2 💤 ±0  0 ❌ ±0 

Results for commit 7ffefaa. ± Comparison against earlier commit eaf4152.