Fixed Virtual environment to Ubuntu 18.04 in CI jobs.

Author: abhiTronix

.github/workflows/builder_0_1.yml

@@ -53,7 +53,7 @@ env:
 jobs:
   builder-base:
     name: Base GCC 32-bit Builder Pi[0-1]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         rpios_types: [stretch, buster]
@@ -99,7 +99,7 @@ jobs:
   builder-cross:
     name: Cross GCC 32-bit Builder Pi[0-1]
     needs: builder-base
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [6.3.0, 8.3.0, 9.3.0, 10.2.0]
@@ -146,7 +146,7 @@ jobs:
   builder-native:
     name: Native GCC 32-bit Builder Pi[0-1]
     needs: [builder-base, builder-cross]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [9.3.0, 10.2.0]

.github/workflows/builder_2_3.yml

@@ -53,7 +53,7 @@ env:
 jobs:
   builder-base:
     name: Base GCC 32-bit Builder Pi[2-3]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         rpios_types: [stretch, buster]
@@ -97,7 +97,7 @@ jobs:
   builder-cross:
     name: Cross GCC 32-bit Builder Pi[2-3]
     needs: builder-base
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [6.3.0, 8.3.0, 9.3.0, 10.2.0]
@@ -144,7 +144,7 @@ jobs:
   builder-native:
     name: Native GCC 32-bit Builder Pi[2-3]
     needs: [builder-base, builder-cross]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [9.3.0, 10.2.0]

.github/workflows/builder_3_plus.yml

@@ -53,7 +53,7 @@ env:
 jobs:
   builder-base:
     name: Base GCC 32-bit Builder Pi[3+]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         rpios_types: [stretch, buster]
@@ -97,7 +97,7 @@ jobs:
   builder-cross:
     name: Cross GCC 32-bit Builder Pi[3+]
     needs: builder-base
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [6.3.0, 8.3.0, 9.3.0, 10.2.0]
@@ -142,7 +142,7 @@ jobs:
   builder-native:
     name: Native GCC 32-bit Builder Pi[3+]
     needs: [builder-base, builder-cross]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [9.3.0, 10.2.0]

.github/workflows/builder_64.yml

@@ -53,7 +53,7 @@ env:
 jobs:
   builder-base:
     name: Base GCC 64-bit Builder Pi[64]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [6.3.0, 8.3.0]
@@ -101,7 +101,7 @@ jobs:
   builder-cross:
     name: Cross GCC 64-bit Builder Pi[64]
     needs: builder-base
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [6.3.0, 8.3.0, 9.3.0, 10.2.0]
@@ -148,7 +148,7 @@ jobs:
   builder-native:
     name: Native GCC 64-bit Builder Pi[64]
     needs: [builder-base, builder-cross]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [9.3.0, 10.2.0]

.github/workflows/builder_x86_64.yml

@@ -52,7 +52,7 @@ env:
 jobs:
   builder-x86_64:
     name: GCC x86_64 Builder Pi[Desktop]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [10.2.0]
@@ -96,7 +96,7 @@ jobs:
 
   builder-x86:
     name: GCC x86 Builder Pi[Desktop]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         gcc_versions: [10.2.0]

.github/workflows/docs.yml

@@ -55,7 +55,7 @@ env:
 jobs:
   builder-docs_root:
     name: Docs Root Deployer
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: before_install
@@ -88,7 +88,7 @@ jobs:
 
   builder-docs_base:
     name: Docs Base Deployer
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: before_install
@@ -143,7 +143,7 @@ jobs:
 
   builder-docs_main:
     name: Docs Main Deployer
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: before_install
@@ -226,7 +226,7 @@ jobs:
 
   builder-docs_experimental:
     name: Docs Root Deployer
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: before_install