ci: Enable experimental kernel stuff in Alpine task

Base the task on --preset=dev-mode to ensure maximal coverage and add
the following:

   bitcoin-chainstate (experimental) ... ON
   libbitcoinkernel (experimental) ..... ON
   kernel-test (experimental) .......... ON

.github/workflows/ci.yml

@@ -516,7 +516,7 @@ jobs:
             timeout-minutes: 120
             file-env: './ci/test/00_setup_env_native_previous_releases.sh'
 
-          - name: 'Alpine (musl), depends, gui'
+          - name: 'Alpine (musl)'
             cirrus-runner: 'ghcr.io/cirruslabs/ubuntu-runner-amd64:24.04-md'
             fallback-runner: 'ubuntu-24.04'
             timeout-minutes: 120

ci/test/00_setup_env_native_alpine_musl.sh

@@ -13,8 +13,7 @@ export PIP_PACKAGES="--break-system-packages pyzmq pycapnp"
 export DEP_OPTS="DEBUG=1"
 export GOAL="install"
 export BITCOIN_CONFIG="\
- -DWITH_ZMQ=ON \
- -DBUILD_GUI=ON \
+ --preset=dev-mode \
  -DREDUCE_EXPORTS=ON \
  -DCMAKE_BUILD_TYPE=Debug \
 "