Updated Alpine Linux version

README.rst

@@ -275,8 +275,8 @@ variable. The default version is dependent on ``MB_ML_LIBC`` and ``PLAT``.
 
 When ``MB_ML_LIBC`` is ``musllinux``:
 
-* ``multibuild/alpine3.17_x86_64``,  when ``PLAT`` is ``x86_64``
-* ``multibuild/alpine3.17_arm64v8``,  when ``PLAT`` is ``aarch64``
+* ``multibuild/alpine3.18_x86_64``,  when ``PLAT`` is ``x86_64``
+* ``multibuild/alpine3.18_arm64v8``,  when ``PLAT`` is ``aarch64``
 
 Otherwise:
 

travis_linux_steps.sh

@@ -122,7 +122,7 @@ function install_run {
         if [ "$MB_ML_LIBC" == "musllinux" ]; then
         	# PLAT is the same as $plat,
         	# unless $plat is "aarch64", in which case it becomes "arm64v8"
-            local docker_image="multibuild/alpine3.17_{PLAT}"
+            local docker_image="multibuild/alpine3.18_{PLAT}"
         elif [ "$plat" == i686 ]; then
             local docker_image="matthewbrett/trusty:32"
         else