CI: various improvements (#517)

* ci: fix SETUP_OPTIONS unset variable error on OpenBSD

OpenBSD's sh treats unset variables as errors. Use ${SETUP_OPTIONS:-}
to default to empty string when the variable is not defined.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* ci: fix several issues in c-cpp workflow

- Fix macOS matrix references: matrix.build.install_packages and
  matrix.build.setup_options had a spurious .build. nesting, causing
  setup options and extra packages to be silently ignored
- OpenBSD: use gettext-tools package name and add -Dnls=false since
  gettext is unavailable there
- Use ${SETUP_OPTIONS:-} in the build job to avoid unset variable errors
- Replace pip install of meson/ninja with apt-get on Ubuntu runners

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* ci: remove freebsd-15-0-snap task from Cirrus CI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: andy5995

.cirrus.yml

@@ -28,16 +28,6 @@ freebsd_task:
     - meson setup builddir
   <<: *common_meson_steps
 
-freebsd_task:
-  <<: *filter_template
-  name: freebsd-15-0-snap
-  freebsd_instance:
-    image_family: freebsd-15-0-snap
-  <<: *common_freebsd_steps
-  setup_script:
-    - meson setup builddir
-  <<: *common_meson_steps
-
 arm_task:
   <<: *filter_template
   arm_container:

.github/workflows/c-cpp.yml

@@ -85,9 +85,8 @@ jobs:
         sudo apt upgrade -y
         sudo apt-get install -y \
           gettext \
-          python3-pip \
-          python3-setuptools
-        sudo -H python3 -m pip install meson ninja
+          meson \
+          ninja-build
 
     - if: ${{ contains(matrix.container, 'alpine') }}
       run: |
@@ -100,7 +99,7 @@ jobs:
         zypper --non-interactive update
 
     - name: Configure
-      run: meson setup builddir $SETUP_OPTIONS ${{ matrix.setup_options }}
+      run: meson setup builddir ${SETUP_OPTIONS:-} ${{ matrix.setup_options }}
 
     - name: Build
       run: |
@@ -122,10 +121,10 @@ jobs:
       with:
         usesh: true
         prepare: |
-          pkg_add gettext git meson ninja
+          pkg_add gettext-tools git meson ninja
 
         run: |
-          meson setup builddir -Db_sanitize=none $SETUP_OPTIONS || cat builddir/meson-logs/meson-log.txt
+          meson setup builddir -Db_sanitize=none -Dnls=false ${SETUP_OPTIONS:-} || cat builddir/meson-logs/meson-log.txt
           cd builddir
           meson compile -v
           meson test -v --suite rmw
@@ -159,10 +158,10 @@ jobs:
           ninja \
           ncurses \
           pkg-config \
-          ${{ matrix.build.install_packages }}
+          ${{ matrix.install_packages }}
 
     - name: Configure
-      run: meson setup builddir ${{ matrix.build.setup_options }}
+      run: meson setup builddir ${{ matrix.setup_options }}
 
     - name: Build
       run: |