ci: enable -Werror

For better feedback on build status and to keep mpv warning free.

Except for macos builds, there are more issue there that need fixing.

ci/build-freebsd.sh

@@ -6,6 +6,8 @@ export CXXFLAGS="$CXXFLAGS -isystem/usr/local/include"
 export LDFLAGS="$LDFLAGS -L/usr/local/lib"
 
 meson setup build \
+    --werror      \
+    -Dc_args="-Wno-error=deprecated -Wno-error=deprecated-declarations" \
     -Dlibmpv=true \
     -Dlua=enabled \
     -Degl-drm=enabled \

ci/build-mingw64.sh

@@ -268,6 +268,8 @@ build=mingw_build
 rm -rf $build
 
 meson setup $build --cross-file "$prefix_dir/crossfile" \
+    --werror                   \
+    -Dc_args="-Wno-error=deprecated -Wno-error=deprecated-declarations" \
     --buildtype debugoptimized \
     -Dlibmpv=true -Dlua=luajit \
     -D{shaderc,spirv-cross,d3d11,libplacebo}=enabled

ci/build-msys2.sh

@@ -1,6 +1,8 @@
 #!/bin/sh -e
 
 meson setup build            \
+  --werror                   \
+  -Dc_args="-Wno-error=deprecated -Wno-error=deprecated-declarations" \
   -D cdda=enabled            \
   -D d3d-hwaccel=enabled     \
   -D d3d11=enabled           \

ci/build-tumbleweed.sh

@@ -2,6 +2,8 @@
 set -e
 
 meson setup build \
+  --werror        \
+  -Dc_args="-Wno-error=deprecated -Wno-error=deprecated-declarations" \
   -Db_sanitize=address,undefined \
   -Dcdda=enabled          \
   -Ddvbin=enabled         \

meson.build

@@ -256,8 +256,6 @@ flags = ['-D_ISOC99_SOURCE', '-D_GNU_SOURCE',
 link_flags = []
 
 test_flags = ['-Werror=implicit-function-declaration',
-              '-Wno-error=deprecated-declarations',
-              '-Wno-error=unused-function',
               '-Wempty-body',
               '-Wdisabled-optimization',
               '-Wstrict-prototypes',