Temporarily disable linux runners on github actions.

Author: arobenko

.github/workflows/actions_build.yml

@@ -9,6 +9,7 @@ env:
 jobs:
 
   build_gcc_old_ubuntu_20_04:
+    if: false
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
@@ -68,6 +69,7 @@ jobs:
         VERBOSE: 1     
 
   build_gcc_ubuntu_20_04:
+    if: false
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
@@ -120,6 +122,7 @@ jobs:
         VERBOSE: 1 
 
   build_gcc_ubuntu_22_04:
+    if: false
     runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
@@ -176,6 +179,7 @@ jobs:
 
 
   build_clang_old_ubuntu_20_04:
+    if: false
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
@@ -240,6 +244,7 @@ jobs:
         VERBOSE: 1 
 
   build_clang_ubuntu_20_04:
+    if: false
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
@@ -297,6 +302,7 @@ jobs:
         VERBOSE: 1 
 
   build_clang_ubuntu_22_04:
+    if: false
     runs-on: ubuntu-22.04
     strategy:
       fail-fast: false