ci: Autodetect if cacche is available to print the stats

Always print the stats if ccache executable exists, this way
we can get rid of one extra env var.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5543>

.gitlab-ci.yml

@@ -252,7 +252,6 @@ commitlint:
 
 .build_ccache_vars:
   variables:
-    HAVE_CCACHE: 'true'
     CCACHE_COMPILERCHECK: 'content'
     CCACHE_COMPRESS: 'true'
     CCACHE_BASEDIR: '/cache/gstreamer/gstreamer'
@@ -518,7 +517,6 @@ build macos:
    - '.macos image'
   variables:
     # gst-libav/ffmpeg throws Wundef errors
-    HAVE_CCACHE: 'false'
     GST_WERROR: "false"
     MESON_ARGS: "${DEFAULT_MESON_ARGS}"
     SUBPROJECTS_CACHE_DIR: "/Users/gst-ci/subprojects"

ci/scripts/build.sh

@@ -10,8 +10,6 @@ set -eux
 # GST_WERROR: make warning fatal or not
 #   must be a string of a boolean, "true" or "false". Not yaml bool.
 # SUBPROJECTS_CACHE_DIR: The location in the image of the subprojects cache
-# HAVE_CCACHE: whether we have ccache available
-#   must be a string of a boolean, "true" or "false". Not yaml bool.
 
 export RUSTUP_HOME="/usr/local/rustup"
 export CARGO_HOME="/usr/local/cargo"
@@ -29,8 +27,18 @@ fi
 
 date -R
 meson setup build/ --native-file ./ci/meson/gst-ci-cflags.ini  ${ARGS}
+date -R
+
+if command -v ccache
+then
+  ccache --show-stats
+fi
+
 date -R
 meson compile -C build/
 date -R
 
-test "$HAVE_CCACHE" = "true" && ccache --show-stats
+if command -v ccache
+then
+  ccache --show-stats
+fi