Installer fixes (#3962)

* Switch variable to make it easier to debug
Fixes #3933

* rename output file

* add setting to directly generate refs

* use prod mode

* fix check

* add debug flags

* remove debug marker

* pre-safe keys

* update installer ref

* split installer steps

* split steps further

* try static adding

* remove split key add

* try dry rn again

* do not dry run keys

* fix debian 11 detection

* add ci to let install run through

* remove flags

* remove dryrun

* run on master

* query api on test

* fix missing env

* use matmair for tests

* use specific version

* remove old python first

* check python version

* add more version checks

* multiline marker for action

* add option to select python env

* set python version before running installer

* cleanup script

* use inline apt for python install

* package 3.9 by default

* remove custom python install

* add some sleeps

* fix package names

* reduce double depb definition

* set python version

* remove 3.9 requirement

* do invoke and wheel install in the right context

* fix typing for 3.8

* use var for config file if it exsists

* fix discovery

* use raw output for jq

* remove tests

* revert change in tasks.py

.pkgr.yml

@@ -15,33 +15,20 @@ env:
   - INVENTREE_PLUGIN_FILE=/opt/inventree/plugins.txt
   - INVENTREE_CONFIG_FILE=/opt/inventree/config.yaml
 after_install: contrib/packager.io/postinstall.sh
+dependencies:
+  - curl
+  - python3
+  - python3-venv
+  - python3-pip
+  - python3-cffi
+  - python3-brotli
+  - python3-wheel
+  - libpango-1.0-0
+  - libharfbuzz0b
+  - libpangoft2-1.0-0
+  - gettext
+  - nginx
+  - jq
 targets:
-  ubuntu-20.04:
-    dependencies:
-      - curl
-      - python3
-      - python3-venv
-      - python3-pip
-      - python3-cffi
-      - python3-brotli
-      - python3-wheel
-      - libpango-1.0-0
-      - libharfbuzz0b
-      - libpangoft2-1.0-0
-      - gettext
-      - nginx
-      - jq
-  debian-11:
-    dependencies:
-      - curl
-      - python3
-      - python3-venv
-      - python3-pip
-      - python3-cffi
-      - python3-brotli
-      - python3-wheel
-      - libpango-1.0-0
-      - libpangoft2-1.0-0
-      - gettext
-      - nginx
-      - jq
+  ubuntu-20.04: true
+  debian-11: true