Fix shebangs of the GDB hooks

Also, use -p (preserve timestamp) and -n (don't create backup files)
with pathfix.py.

Resolves https://bugzilla.redhat.com/show_bug.cgi?id=1560295

python3.spec

@@ -988,8 +988,9 @@ sed -i -e "s/'pyconfig.h'/'%{_pyconfig_h}'/" \
 # Switch all shebangs to refer to the specific Python version.
 LD_LIBRARY_PATH=./build/optimized ./build/optimized/python \
   Tools/scripts/pathfix.py \
-  -i "%{_bindir}/python%{pybasever}" \
-  %{buildroot}
+  -i "%{_bindir}/python%{pybasever}" -pn \
+  %{buildroot} \
+  %{?with_gdb_hooks:%{buildroot}$DirHoldingGdbPy/*.py}
 
 # Remove shebang lines from .py files that aren't executable, and
 # remove executability from .py files that don't have a shebang line: