[meson] Remove `default_library=both` from `default_options`.

It is inconsistent with what all other Meson projects do.

It also prevents static linking to FreeType when it is a subproject because
`default_options` in a subproject takes precedence on values set on the main
project.  For example, building 'GStreamer' with `-Ddefault_library=static`
would still dynamically link on FreeType unless the user also sets
`-Dfreetype2:default_library=static`.

* meson.build: Updated.

* .gitlab-ci.yml: Retain `both` option for testing.
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e8f8443..10de446 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,7 @@
 
 # FIXME: Use --werror once warnings are fixed.
 variables:
-  MESON_ARGS: --fatal-meson-warnings
+  MESON_ARGS: --fatal-meson-warnings --default-library=both
   MESON_ARGS_WINDOWS: ${MESON_ARGS} --force-fallback-for=zlib
 
 .build windows common:
@@ -147,7 +147,8 @@
 linux meson:
   extends: '.build linux common'
   script: |
-    meson setup build -Dbrotli=disabled \
+    meson setup build ${MESON_ARGS} \
+                      -Dbrotli=disabled \
                       -Dbzip2=disabled \
                       -Dharfbuzz=disabled \
                       -Dpng=disabled \
@@ -159,7 +160,8 @@
 linux meson libs:
   extends: '.build linux common'
   script: |
-    meson setup build -Dbrotli=enabled \
+    meson setup build ${MESON_ARGS} \
+                      -Dbrotli=enabled \
                       -Dbzip2=enabled \
                       -Dharfbuzz=disabled \
                       -Dpng=disabled \
@@ -222,7 +224,7 @@
     - pip3 install -U meson
     - pip3 install --upgrade certifi
     - pip3 install -U ninja
-    
-    - meson setup build
+
+    - meson setup build ${MESON_ARGS}
     - meson compile --verbose -C build
     - sudo meson install -C build
diff --git a/meson.build b/meson.build
index 5bf94c3..a066325 100644
--- a/meson.build
+++ b/meson.build
@@ -25,7 +25,6 @@
 
 project('freetype2', 'c',
   meson_version: '>= 0.55.0',
-  default_options: ['default_library=both'],
   version: run_command('builds/meson/extract_freetype_version.py',
                        'include/freetype/freetype.h',
                        check: true).stdout().strip(),