meson: Apply formatting universally

Now that we have applied the [1] patch, the diff is much
nicer and less noisy.

[1]: https://www.github.com/mesonbuild/meson/pull/14861

src/libmain/meson.build

@@ -1,4 +1,6 @@
-project('nix-main', 'cpp',
+project(
+  'nix-main',
+  'cpp',
   version : files('.version'),
   default_options : [
     'cpp_std=c++2a',
@@ -16,8 +18,7 @@ subdir('nix-meson-build-support/deps-lists')
 
 configdata = configuration_data()
 
-deps_private_maybe_subproject = [
-]
+deps_private_maybe_subproject = []
 deps_public_maybe_subproject = [
   dependency('nix-util'),
   dependency('nix-store'),
@@ -43,7 +44,7 @@ int main() {
 configdata.set(
   'HAVE_PUBSETBUF',
   cxx.compiles(pubsetbuf_test).to_int(),
-  description: 'Optionally used for buffering on standard error'
+  description : 'Optionally used for buffering on standard error',
 )
 
 config_priv_h = configure_file(
@@ -78,7 +79,7 @@ this_library = library(
   config_priv_h,
   dependencies : deps_public + deps_private + deps_other,
   include_directories : include_dirs,
-  link_args: linker_export_flags,
+  link_args : linker_export_flags,
   prelink : true, # For C++ static initializers
   install : true,
 )