configure_file can not replace variables after "\\"

Describe the bug
confugre_file can not replace the @@ variables after \\ with meson 1.5.2.

To Reproduce

meson.build

project('test')

test_conf = configuration_data()
test_conf.set('A', 'str_a')
test_conf.set('B', 'str_b')

configure_file(input : 'test.h.in',
               output : 'test.h',
               configuration : test_conf)

test.h.in

const char *TEST_STR = "@A@\\\\@B@";

When you type meson setup build, meson 1.5.2 replaces only @A@.

const char *TEST_STR = "str_a\\@B@";

Expected behavior
test.h should be like this

const char *TEST_STR = "str_a\\str_b";

meson had the expected behavior at least three months ago (maybe 1.4.1)

system parameters

• Is this a cross build or just a plain native build (for the same computer)?
  native build
• what operating system (e.g. MacOS Catalina, Windows 10, CentOS 8.0, Ubuntu 18.04, etc.)
  Windows 10
• what Python version are you using e.g. 3.8.0
  3.12.2
• what meson --version
  1.5.2
• what ninja --version if it's a Ninja build
  not ninja build

Start by reproducing the issue with the meson.build and test.h.in examples using Meson 1.5.2 on the reported native Windows setup. Trace configure_file substitution for @@ variables following escaped backslashes, then verify that both @A@ and @B@ are replaced and the output matches the expected C string.