Catch SIGTERM and kill running process before exitting

[samuelcolvin]

No description provided.

[codecov]

Codecov Report

Merging #244 (a5530bf) into main (ea31274) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #244   +/-   ##
=======================================
  Coverage   99.51%   99.51%           
=======================================
  Files           6        6           
  Lines         411      416    +5     
  Branches       83       82    -1     
=======================================
+ Hits          409      414    +5     
  Misses          1        1           
  Partials        1        1           

Files Changed	Coverage Δ
watchfiles/run.py	100.00% <100.00%> (ø)

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ea31274...a5530bf. Read the comment docs.