Using `__del__` often closes the database on a different thread, which
is not supported by the sqlite module and produces a different warning.
Explicitly close the status database everywhere it is used.
otherwise, when trying to run `pytest` in a `python3.13` environment
results in a bunch of
```
tests/unit/sync/test_sync.py::test_partial_sync_ignore
/home/user/.asdf/installs/python/3.13.1/lib/python3.13/asyncio/base_events.py:650: ResourceWarning: unclosed database in <sqlite3.Connection object at 0x7fda8f6b6c50>
sys.set_asyncgen_hooks(
Enable tracemalloc to get traceback where the object was allocated.
See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.
```
Installing on Python 3.7 no longer works due to lack of support in the
minimal version of setuptools_scm. This commit makes the change
official, but it happened a while ago.
Hypothesis found the following example:
```
tests/unit/utils/test_vobject.py:335: in add_prop
assert c[key] == value
E AssertionError: assert '0' == '1'
E
E - 1
E + 0
E Falsifying example:
E state = VobjectMachine()
E unparsed_0 = state.get_unparsed_lines(encoded=False, joined=False)
E parsed_0 = state.parse(unparsed=unparsed_0)
E state.add_prop_raw(c=parsed_0, key='0', params=[], value='0')
E state.add_prop_raw(c=parsed_0, key='0', params=[], value='0')
E state.add_prop(c=parsed_0, key='0', value='1')
E state.teardown()
```
After the two `add_prop_raw` calls, `c.props` is `["0;:0", "0;:0",
"FOO:YES"]`. `_Component.__delitem__` then fails to effectively delete
the previous key: it deletes the first `"0;:0"` item, but then checks
for continuation lines following it and incorrectly keeps the second
`"0;:0"` item even though it begins with one of the prefixes it's trying
to delete. Checking for the prefix in the check for continuation lines
fixes this.
Fixes: #1149
This allows users to process fetched items through a filter command,
to fix malformed webcal items as they are imported.
In my case, my provider adds the export time to the description and
random sequence numbers to all events. This caused the whole collection
to be invalidated and propagated at each sync. I use the filter to
remove those, canonicalising the items.
