Increase default value of initial-fetch-depth to 100

For most situation it should be enough to find merge base. Previous value was too slow and overhead of doing fetch was significantly higher than saving of transfer.

action.yml

@@ -38,7 +38,7 @@ inputs:
       until the merge-base is found or there are no more commits in the history.
       This option takes effect only when changes are detected using git against different base branch.
     required: false
-    default: '10'
+    default: '100'
 outputs:
   changes:
     description: JSON array with names of all filters matching any of changed files