Updated the github_env to accomodate ubuntu

.github/scripts/build_assets/github_env.py

@@ -1,24 +1,33 @@
 import os
+import platform
 
 
 def set_env_var(key: str, value: str, delimiter: str='~'):
     """
     Set the GitHub env variable of 'key' to 'value' using
     the method specified here:
     https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable
+    Support both Windows and Ubuntu machines provided by GitHub Actions.
 
-    Note: This assumes that we are on a Windows machine.
     :param: key, the name of the env variable.
     :param: value, the value of the env variable.
     :param: delimiter, the delimiter that you want to use
     to write to the file. Only applicable if the 'value' contains
     '\n' character aka a multiline string.
     """
-    print('echo "{key}={value}" >> %GITHUB_ENV%')
+    print(platform.system())
 
-    if "\n" in value:
-        os.system(f'echo "{key}<<{delimiter}" >> %GITHUB_ENV%')
-        os.system(f'echo {value} >> %GITHUB_ENV%')
-        os.system(f'echo "{delimiter}" >> %GITHUB_ENV%')
+    if platform.system() == "Windows":
+        if "\n" in value:
+            os.system(f'echo "{key}<<{delimiter}" >> %GITHUB_ENV%')
+            os.system(f'echo {value} >> %GITHUB_ENV%')
+            os.system(f'echo "{delimiter}" >> %GITHUB_ENV%')
+        else:
+            os.system(f'echo "{key}={value}" >> %GITHUB_ENV%')
     else:
-        os.system(f'echo "{key}={value}" >> %GITHUB_ENV%')
+        if "\n" in value:
+            os.system(f'echo "{key}<<{delimiter}" >> $GITHUB_ENV')
+            os.system(f'echo {value} >> $GITHUB_ENV')
+            os.system(f'echo "{delimiter}" >> $GITHUB_ENV')
+        else:
+            os.system(f'echo "{key}={value}" >> $GITHUB_ENV')