Known Transmute Tech debt

### Are there any linked Issues or Pull Requests?

_No response_

### Brief description

Lifted from https://code.metoffice.gov.uk/trac/lfric_apps/ticket/906

Once psytrans releases, delete duplicate local copies and python path in PSyTran.

Functions to do
Functions in [813](https://code.metoffice.gov.uk/trac/lfric_apps/ticket/813) used for Spectral GWD:

is_heavy_loop
get_outer_loops
parallel_regions_for_clustered_loops
expr_contains_member
omp_do_for_heavy_loops
mark_explicit_privates
add_parallel_do_over_meta_segments
[#971](https://code.metoffice.gov.uk/trac/lfric_apps/ticket/971) Transmute Soc Kernel

replace_n_threads
first_priv_red_init
[#788](https://code.metoffice.gov.uk/trac/lfric_apps/ticket/788) Transmute Gregory-Rowntree convection

#971 Transmute Soc Kernel
{{{
add_omp_parallel_region
}}}

### Further details of the issue.

_No response_