[Bug] Avoid losing worker slot on error while processing cache eviction

[dandavison]

Improve the situation described here:

sdk-python/temporalio/worker/_workflow.py

Lines 270 to 277 in 49ca10e

	except Exception as err:
	# We cannot fail a cache eviction, we must just log and not complete
	# the activation (failed or otherwise). This should only happen in
	# cases of deadlock or tasks not properly completing, and yes this
	# means that a slot is forever taken.
	# TODO(cretz): Should we build a complex mechanism to continually
	# try the eviction until it succeeds?
	if cache_remove_job: