chore(GH): pin ubuntu (22.04) version for gh runners

Currently, ubuntu:latest uses Ubuntu version 24.04, which includes
kernel 6.8. Since Tracee needs to be tested with kernel 6.8, it is
better to pin the version of the Ubuntu runners.

After testing Tracee with kernel 6.8 and confirming that everything
works correctly, this commit can be reverted.

.github/workflows/pr.yaml

@@ -84,7 +84,7 @@ jobs:
   #
   verify-docs:
     name: Verify Documentation
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -128,7 +128,7 @@ jobs:
   #
   verify-analyze-code:
     name: Verify and Analyze Code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -167,7 +167,7 @@ jobs:
     name: Verify Signatures
     needs:
       - verify-analyze-code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -188,7 +188,7 @@ jobs:
     name: Verify Other Tools
     needs:
       - verify-analyze-code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -219,7 +219,7 @@ jobs:
     name: Unit Tests
     needs:
       - verify-analyze-code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -237,7 +237,7 @@ jobs:
     name: Integration Tests
     needs:
       - verify-analyze-code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -255,7 +255,7 @@ jobs:
     name: Performance Tests
     needs:
       - verify-analyze-code
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout Code
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
@@ -274,7 +274,7 @@ jobs:
     #needs:
     #  - verify-signatures
     #  - verify-tools
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     outputs:
       matrix01: ${{ steps.set-matrix.outputs.matrix01 }}
     steps: