Use the version of pv installed on the system rather than the ./pv from 
the development tree as is done when running 'make check'.

Upstream-Status: Inappropriate [x-compile specific]

---
diff -Naur pv-1.9.31.orig/tests/test-env.sh pv-1.9.31/tests/test-env.sh
--- pv-1.9.31.orig/tests/test-env.sh	2024-12-07 08:59:43.000000000 -0500
+++ pv-1.9.31/tests/test-env.sh	2025-03-26 14:11:30.987123378 -0400
@@ -9,7 +9,7 @@
 true "${srcdir:?not set - call this from 'make check'}"
 
 # Parameters.
-testSubject="./pv"
+testSubject="pv"
 sourcePath="${srcdir}"
 
 # Set everything to the "C" locale.