🔨 [dataset] Handle corrupted cached file in PersistentDataset (#7244)

Fixes #5723

### Description
Corrupted cached files in the PersistentDataset cause the exception:
`RuntimeError: Invalid magic number; corrupt file?`

With this PR we handle that case in the try-except block and continue
the usual functionality if the cached file was absent.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [x] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [x] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

---------

Signed-off-by: Ishan Dutta <ishandutta0098@gmail.com>
Co-authored-by: YunLiu <55491388+KumoLiu@users.noreply.github.com>

monai/data/dataset.py

@@ -387,6 +387,12 @@ def _cachecheck(self, item_transformed):
             except PermissionError as e:
                 if sys.platform != "win32":
                     raise e
+            except RuntimeError as e:
+                if "Invalid magic number; corrupt file" in str(e):
+                    warnings.warn(f"Corrupt cache file detected: {hashfile}. Deleting and recomputing.")
+                    hashfile.unlink()
+                else:
+                    raise e
 
         _item_transformed = self._pre_transform(deepcopy(item_transformed))  # keep the original hashed
         if hashfile is None: