Drop request_counts table

The table is unused since CAPI 1.120.0 (Oct. 2021) and the corresponding
model class has been removed with CAPI 1.140.0 (Oct. 2022).

Author: philippthun

db/migrations/20240521143700_drop_request_counts_table.rb

@@ -0,0 +1,7 @@
+Sequel.migration do
+  change do
+    # This table is unused since CAPI 1.120.0 (Oct. 2021).
+    # The model class has been removed with CAPI 1.140.0 (Oct. 2022).
+    drop_table?(:request_counts)
+  end
+end