[pre-commit] Add codespell-clean gdb/testsuite dirs

The following gdb/testsuite subdirs are codespell-clean:
...
$ for d in gdb/testsuite/gdb.*; do \
      echo -n "$d:"; \
      codespell --config ./gdb/contrib/setup.cfg $d \
          | wc -l; \
  done 2>&1 \
  | grep :0
gdb/testsuite/gdb.ctf:0
gdb/testsuite/gdb.dap:0
gdb/testsuite/gdb.gdb:0
gdb/testsuite/gdb.go:0
gdb/testsuite/gdb.modula2:0
gdb/testsuite/gdb.objc:0
gdb/testsuite/gdb.opencl:0
gdb/testsuite/gdb.perf:0
gdb/testsuite/gdb.replay:0
gdb/testsuite/gdb.server:0
gdb/testsuite/gdb.testsuite:0
...

Add them to the pre-commit configuration.

Approved-By: Tom Tromey <tom@tromey.com>