when generating new matching on RM, clear report

app/workflows/record_matching/workflow.py

@@ -144,6 +144,7 @@ def att_ui(i):
                     name_similarity = st.number_input('Matching name similarity (min)', min_value=0.0, max_value=1.0, step=0.01, value=sv.matching_sentence_pair_jaccard_threshold.value, help='The minimum Jaccard similarity between the character trigrams of the names of two records for them to be considered a match. Higher values will result in fewer closer name matches.')
 
                 if st.button('Detect record groups', use_container_width=True):
+                    sv.matching_evaluations.value = pl.DataFrame()
                     if record_distance != sv.matching_sentence_pair_embedding_threshold.value:
                         sv.matching_sentence_pair_embedding_threshold.value = record_distance
                     if name_similarity != sv.matching_sentence_pair_jaccard_threshold.value: