libpqxx broken by the update: reinplace: couldn't read file

[barracuda156]

--->  Fetching distfiles for libpqxx
--->  libpqxx-7.9.2.tar.gz does not exist in /opt/local/var/macports/distfiles/libpqxx
--->  Attempting to fetch libpqxx-7.9.2.tar.gz from https://github.com/jtv/libpqxx/archive/7.9.2
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100  756k    0  756k    0     0   527k      0 --:--:--  0:00:01 --:--:-- 3968k
--->  Verifying checksums for libpqxx
--->  Checksumming libpqxx-7.9.2.tar.gz
--->  Extracting libpqxx
--->  Extracting libpqxx-7.9.2.tar.gz
Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_databases_libpqxx/libpqxx/work" && /usr/bin/gzip -dc '/opt/local/var/macports/distfiles/libpqxx/libpqxx-7.9.2.tar.gz' | /usr/bin/gnutar --no-same-owner -xf - 
--->  Patching splitconfig: s| /usr/bin/env python3|/opt/local/bin/python3.11|
Error: reinplace: couldn't read file "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_databases_libpqxx/libpqxx/work/libpqxx-7.9.2/tools/splitconfig": no such file or directory
Error: Failed to patch libpqxx: reinplace sed(1) failed

[Sergey Fedorov <barracuda@…>]

In e5b0df4da848a8abbfeaa5d437a42d5d94ad99c5/macports-ports (master):

libpqxx: unbreak port after recent update

Closes: #70575