feat: Integrate single kernel (#541)

## Issue

Needs to integrate the new refactoring using the single kernel charm

## Solution

Integrate the single kernel library

.github/workflows/ci.yaml

@@ -24,7 +24,7 @@ jobs:
 
   unit-test:
     name: Unit test charm
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     timeout-minutes: 10
     steps:
       - name: Checkout
@@ -81,6 +81,18 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+      - name: (GitHub hosted) Free up disk space
+        timeout-minutes: 1
+        run: |
+          printf '\nDisk usage before cleanup\n'
+          df --human-readable
+          # Based on https://github.com/actions/runner-images/issues/2840#issuecomment-790492173
+          rm -r /opt/hostedtoolcache/
+          printf '\nDisk usage after cleanup\n'
+          df --human-readable
+      - name: (self hosted) Disk usage
+        timeout-minutes: 1
+        run: df --human-readable
       - name: Install terraform snap
         run: |
           sudo snap install terraform --channel=latest/stable --classic

.gitignore

@@ -1,6 +1,7 @@
 /requirements.txt
 /requirements-last-build.txt
 /charm_internal_version
+/charm_version.backup
 
 *.idea
 .vscode/

charmcraft.yaml

@@ -96,4 +96,3 @@ parts:
       - LICENSE
       - charm_version
       - workload_version
-      - templates