ci: migrate GitHub Actions workflows to ubuntu-slim (#111)

Author: joschi

.github/workflows/dash0.yml

@@ -10,7 +10,7 @@ on:
 
 jobs:
   otel-export-dash0:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     steps:
       - uses: actions/checkout@v7
       - name: Export workflow to Dash0

.github/workflows/test.yml

@@ -8,7 +8,7 @@ on:
     - main
 jobs:
   test:
-    runs-on: 'ubuntu-latest'
+    runs-on: 'ubuntu-slim'
     steps:
     - uses: actions/checkout@v7
     - name: Install dependencies

.github/workflows/update.yml

@@ -11,7 +11,7 @@ concurrency:
   cancel-in-progress: true
 jobs:
   update:
-    runs-on: 'ubuntu-latest'
+    runs-on: 'ubuntu-slim'
     steps:
     - uses: actions/checkout@v7
     - name: Install dependencies

.github/workflows/validate.yml

@@ -8,7 +8,7 @@ concurrency:
   cancel-in-progress: true
 jobs:
   validate:
-    runs-on: 'ubuntu-latest'
+    runs-on: 'ubuntu-slim'
     steps:
     - uses: actions/checkout@v7
     - name: Install dependencies