Backport 2.7: Use "#!/usr/bin/env perl" as shebang line.
diff --git a/tests/scripts/check-doxy-blocks.pl b/tests/scripts/check-doxy-blocks.pl
index b0fd696..4967699 100755
--- a/tests/scripts/check-doxy-blocks.pl
+++ b/tests/scripts/check-doxy-blocks.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 
 # Detect comment blocks that are likely meant to be doxygen blocks but aren't.
 #