pgsql: Sync pg_bsd_indent's copyright notices with Postgres practice.

Sync pg_bsd_indent's copyright notices with Postgres practice.

To avoid confusion, make the copyright notices in these files
match the 3-clause form of the BSD license, per the blanket
policy update that UC Berkeley issued years ago.

Discussion: https://postgr.es/m/3935719.1675967430@sss.pgh.pa.us
Discussion: https://postgr.es/m/20230123011002.fzcaa3krql3mqsfn@awork3.anarazel.de

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b44e5fced3e5a6d3d971a51757a306eacc349bf3

Modified Files
--------------
src/tools/pg_bsd_indent/README         | 37 ++++++++++++++++++++++++++++++++++
src/tools/pg_bsd_indent/args.c         |  6 +-----
src/tools/pg_bsd_indent/indent.c       |  6 +-----
src/tools/pg_bsd_indent/indent_codes.h |  6 +-----
src/tools/pg_bsd_indent/indent_globs.h |  6 +-----
src/tools/pg_bsd_indent/io.c           |  6 +-----
src/tools/pg_bsd_indent/lexi.c         |  6 +-----
src/tools/pg_bsd_indent/parse.c        |  6 +-----
src/tools/pg_bsd_indent/pr_comment.c   |  6 +-----
9 files changed, 45 insertions(+), 40 deletions(-)