Revert "Temporarily disable linux runners on github actions."

This reverts commit 4385162.

Author: arobenko

.github/workflows/actions_build.yml

@@ -9,7 +9,6 @@ on:
 
 jobs:
   build_gcc_ubuntu_22_04:
-    if: false
     runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
@@ -51,7 +50,6 @@ jobs:
       run: ctest -V 
 
   build_gcc_ubuntu_24_04:
-    if: false
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
@@ -101,7 +99,6 @@ jobs:
       run: make doc_comms       
 
   build_clang_ubuntu_22_04:
-    if: false
     runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
@@ -143,7 +140,6 @@ jobs:
       run: ctest -V 
 
   build_clang_ubuntu_24_04:
-    if: false
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false