Merge bitcoin#17833: doc: Added running functional tests in valgrind

155a11f doc: Added running functional tests in valgrind (Elichai Turkel)

Pull request description:

  Technically the notes only show an "example" of how to run valgrind with the suppression file,
  but now that bitcoin#17633 is merged then maybe this can encourage more people to run also the functional tests in valgrind

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Tree-SHA512: b8417249b720d0ed5e10b732648f2e07e8889bfc7aa7e94192d1c049b4b7837971678d30c535f273c227848f1290cf11e14369fd6c1924b734f2e47e2af41401

doc/developer-notes.md

@@ -256,6 +256,7 @@ $ valgrind --suppressions=contrib/valgrind.supp src/test/test_dash
 $ valgrind --suppressions=contrib/valgrind.supp --leak-check=full \
       --show-leak-kinds=all src/test/test_dash --log_level=test_suite
 $ valgrind -v --leak-check=full src/dashd -printtoconsole
+$ ./test/functional/test_runner.py --valgrind
 ```
 
 ### Compiling for test coverage