meson.build: require Meson 0.56

Meanwhile, Meson 0.56 is really old and doesn't understand "meson
compile".  Let's upgrade the required version and drop the Ubuntu
20.04 CI build.

.github/workflows/build.yml

@@ -40,13 +40,6 @@ jobs:
             ldflags:
             packages: g++-11
             meson_options:
-          - compiler: gcc10
-            os: ubuntu-20.04
-            cc: gcc-10
-            cxx: g++-10
-            ldflags:
-            packages: g++-10
-            meson_options:
           - compiler: clang
             os: ubuntu-24.04
             cc: clang

NEWS

@@ -1,4 +1,5 @@
 ncmpc 0.50 - not yet released
+* build: require Meson 0.56
 * lyrics/musixmatch: add new lyrics extension
 * lyrics/google: fix partial loading of lyrics
 

README.rst

@@ -16,7 +16,7 @@ You need:
 - a C++20 compliant compiler (e.g. gcc or clang)
 - `libmpdclient <https://www.musicpd.org/libs/libmpdclient/>`__ 2.16
 - `ncurses <https://www.gnu.org/software/ncurses/>`__
-- `Meson 0.49 <http://mesonbuild.com/>`__ and `Ninja <https://ninja-build.org/>`__
+- `Meson 0.56 <http://mesonbuild.com/>`__ and `Ninja <https://ninja-build.org/>`__
 
 Optional:
 

meson.build

@@ -1,6 +1,6 @@
 project('ncmpc', 'cpp',
   version: '0.50',
-  meson_version: '>= 0.49',
+  meson_version: '>= 0.56',
   default_options: [
     'cpp_std=c++2a',
     'warning_level=3',