meson: disable .pyc bytecode for u_format_table.py

This prevents the creation of src/gallium/auxiliary/util/__pycache__/
which is untracked in git.

The directory in question could be added to .gitignore instead, but
since the script is only executed once, it doesn't seem worthwhile to
write bytecode to disk anyway.

Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

src/gallium/meson.build

@@ -74,7 +74,7 @@ u_format_table_c = custom_target(
    'u_format_table.c',
    input : ['auxiliary/util/u_format_table.py', 'auxiliary/util/u_format.csv'],
    output : 'u_format_table.c',
-   command : [prog_python, '@INPUT@'],
+   command : [prog_python, '-B', '@INPUT@'],
    depend_files : files('auxiliary/util/u_format_parse.py'),
    capture : true,
 )