Move from python2 compliant IOError and EnvironmentError to python3-only OSError (#48764)

* IOError -> OSError

* also do EnvironmentError

lib/spack/llnl/util/lock.py

@@ -391,7 +391,7 @@ def _poll_lock(self, op: int) -> bool:
 
             return True
 
-        except IOError as e:
+        except OSError as e:
             # EAGAIN and EACCES == locked by another process (so try again)
             if e.errno not in (errno.EAGAIN, errno.EACCES):
                 raise