You can identify the encoding used for the file (in this case sql file) using an editor (I used Visual studio code). Once you open the file, it shows you the encoding of the file at the lower right corner on the editor.
I had this issue when I was trying to check-in a file that was encoded UTF-BOM (originating from a non-windows machine) that had special characters appended to individual string characters
You can change the encoding of your file as follows:
In the bottom bar of VSCode, you'll see the label UTF-8 With BOM. Click it. A popup opens. Click Save with encoding. You can now pick a new encoding for that file (UTF-8)