build: subpackages implementation (#164)

* migrate to hatch

* reorder tests

* generic fixtures

* straight forward conftest

* fix docs generation

* fix tox environments

* reformat tomls

* cleanup pyproject

* some play with renaming

* move root conftest into pytest plugins

* fix setup script

* move fixtures to __init__.py

* remove duplicate fixtures

* disable pylint warning

* simplify configuration fixture

* remove empty conftest

* remove crap from local pyprojects

archlinux/ahriman.install

@@ -0,0 +1,53 @@
+post_upgrade() {
+    local breakpoints=(
+        2.9.0-1
+        2.12.0-1
+        2.16.0-1
+    )
+
+    for v in "${breakpoints[@]}"; do
+        if [[ $(vercmp "$v" "$2") -ne "-1" ]]; then
+            "_${v//[.-]/_}_changes"
+        fi
+    done
+}
+
+_2_9_0_1_changes() {
+    cat << EOF
+It was found that there was an upgrade from old devtools package to the new one, which requires manual intervention:
+
+* make sure that devtools are upgraded to the latest release;
+* merge upstream configuration into local configuration (e.g. by using pacdiff);
+* run setup command (i.e. ahriman service-setup) with the same arguments as did before;
+* remove build chroot, e.g.: ahriman service-clean --chroot;
+* update local databases: ahriman update --no-aur --no-local --no-manual -yy.
+
+For more information kindly refer to migration notes https://ahriman.readthedocs.io/en/stable/migrations/2.9.0.html.
+EOF
+}
+
+_2_12_0_1_changes() {
+    cat << EOF
+Whereas old local tree is still supported it is highly recommended to migrate to the new one:
+
+* stop and disable all services;
+* run service-tree-migrate as ahriman user;
+* edit local configuration to avoid pointing to the old paths;
+* run setup command (i.e. ahriman service-setup) with the same arguments as did before;
+* update remote services in order to support new paths (or setup redirects) if any;
+* enable web and timer services again by using x86_64-aur suffix,
+  where x86_64 is the repository architecture and aur is the repository name.
+
+For more information kindly refer to migration notes https://ahriman.readthedocs.io/en/stable/migrations/2.12.0.html.
+EOF
+}
+
+_2_16_0_1_changes() {
+    cat << EOF
+In order to prepare to python 3.13 the project now uses bcrypt instead of passlib for generating and validating
+passwords, because the passlib seems to be unmaintained and will be broken since then. If you are using password
+authentication, you'd need to generate passwords again.
+
+For more information kindly refer to migration notes https://ahriman.readthedocs.io/en/stable/migrations/2.16.0.html.
+EOF
+}