ci/openbsd: bump to 7.5 and remove libplacebo subproject

The available version is enough now.

.github/workflows/build.yml

@@ -413,10 +413,10 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Test in OpenBSD VM
-      uses: cross-platform-actions/[email protected]3.0
+      uses: cross-platform-actions/[email protected]4.0
       with:
         operating_system: openbsd
-        version: '7.4'
+        version: '7.5'
         run: |
             sudo pkg_add -U \
                 cmake \
@@ -428,6 +428,7 @@ jobs:
                 libcdio-paranoia \
                 libdvdnav \
                 libiconv \
+                libplacebo \
                 libv4l \
                 libxkbcommon \
                 luajit \
@@ -454,7 +455,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Test in FreeBSD VM
-      uses: cross-platform-actions/[email protected]3.0
+      uses: cross-platform-actions/[email protected]4.0
       with:
         operating_system: freebsd
         version: '14.0'

ci/build-openbsd.sh

@@ -1,14 +1,9 @@
 #!/bin/sh
 set -e
 
-# libplacebo on openBSD is too old; use a subproject
+# FFmpeg on openBSD (4.4.4) is too old; use a subproject
 rm -rf subprojects
 mkdir -p subprojects
-git clone https://code.videolan.org/videolan/libplacebo.git \
-    --recurse-submodules --shallow-submodules \
-    --depth=1 --recurse-submodules subprojects/libplacebo
-
-# FFmpeg on openBSD (4.4.4) is too old; use a subproject
 cat <<EOF > subprojects/ffmpeg.wrap
 [wrap-git]
 url = https://gitlab.freedesktop.org/gstreamer/meson-ports/ffmpeg.git