Relax exact-version gdal dependency

.buildkite/_compile.sh

@@ -3,7 +3,7 @@ set -eu
 
 DEB_VER=$1
 # pinned because there's also a 3.8.x in the repos and we still want to build against 3.6.x
-GDAL_VER=3.6.4+kx-ci364-git20240110.6c7ffa44c2
+MIN_GDAL_VER=3.6.4+kx-ci364-git20240110.6c7ffa44c2
 
 source /etc/lsb-release
 
@@ -12,10 +12,10 @@ apt-get install -y --no-install-recommends \
     file \
     libcurl4-openssl-dev \
     libgeotiff-dev \
-    "libgdal-dev=${GDAL_VER}" \
-    "libgdal32=${GDAL_VER}" \
-    "gdal-plugins=${GDAL_VER}" \
-    "gdal-data=${GDAL_VER}"
+    "libgdal-dev=${MIN_GDAL_VER}" \
+    "libgdal32=${MIN_GDAL_VER}" \
+    "gdal-plugins=${MIN_GDAL_VER}" \
+    "gdal-data=${MIN_GDAL_VER}"
 
 # install modern cmake
 CMAKE_VER=3.24.1
@@ -37,7 +37,7 @@ cmake -S /src -B . \
     [email protected] \
     -DCPACK_DEBIAN_PACKAGE_SHLIBDEPS=ON \
     -DCPACK_DEBIAN_PACKAGE_GENERATE_SHLIBS=ON \
-    -DCPACK_DEBIAN_PACKAGE_GENERATE_SHLIBS_POLICY="=" \
+    -DCPACK_DEBIAN_PACKAGE_GENERATE_SHLIBS_POLICY=">=" \
     -DCPACK_DEBIAN_FILE_NAME=DEB-DEFAULT
 
 # compile