Remove base_path from model card.

the base_path is stored as `PosixPath` and therefore leads to issues between windows & linux.
This is something that we already fixed in the past see [this PR](https://github.com/flairNLP/flair/pull/2998) but seems to have been reintroduced.
Removing the base_path from the model-card does not remove any important information but fixes issues loading the model on different OS.

pytorch_model.bin

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:210e5cd5d4473d595f7cdd2027fafeff8542fb221f4c5083bef46d1049a14768
-size 433762541
+oid sha256:3499928d9f0c659baa2e9a298aeea5c1daa061f069f1fc08a778071fb1d2a3c6
+size 433759793