fact gathering, prevent "UnboundLocalError: local variable 'datafile' referenced before assignment" when open(path) fails. (#76751)

Co-authored-by: jean kahrs <j.kahrs@hosting.de>

changelogs/fragments/76751-facts-check-datafile-before-close.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - gather_facts - Fact gathering now continues even if it fails to read a file

lib/ansible/module_utils/facts/utils.py

@@ -32,6 +32,7 @@ def get_file_content(path, default=None, strip=True):
     '''
     data = default
     if os.path.exists(path) and os.access(path, os.R_OK):
+        datafile = None
         try:
             datafile = open(path)
             try:
@@ -55,7 +56,8 @@ def get_file_content(path, default=None, strip=True):
             # ignore errors as some jails/containers might have readable permissions but not allow reads
             pass
         finally:
-            datafile.close()
+            if datafile is not None:
+                datafile.close()
 
     return data