Tools/Parser: Silence a warning about using a deprecated directive

Tools/Parser: Silence a warning about using a deprecated directive

This patch fixes the following warning about using a deprecated
directive, '%pure-parser'. Note that '%pure-parser' is deprecated since
Bison 2.3b (bison_min_version defined in meson.build is 2.4).

../tools/development/parser/grammar.y:372.1-12: warning: deprecated directive: ‘%pure-parser’, use ‘%define api.pure’ [-Wdeprecated]
  372 | %pure-parser
      | ^~~~~~~~~~~~
      | %define api.pure
../tools/development/parser/grammar.y: warning: fix-its can be applied.  Rerun with option '--update'. [-Wother]

Signed-off-by: Wook Song <wook16.song@samsung.com>