I am not 100% sure if what OP meant is just to refer to the indentation in the editor (namely, VSC) or if, by this:
i.e. the string ends up indented, which seems what you almost never want - why have an arbitrary amount of white space on the next line of this string?
...they also meant to refer to the actual output of the multi-line string,
(or also, just in case anybody else finds this post looking for a way to avoid this affecting the actual output of the multi-line string), I'd like to add as a complementary answer (cannot comment yet) that this was already beautifully answered here.
If that's the case and you're reading this for that reason, in short, all you want is to import the standard lib 'inspect' and post-process your string with it, using the cleandoc method.
Without breaking the indentation in your IDE, this method makes sure to give you the string output you actually expected:
All leading whitespace is removed from the first line. Any leading whitespace that can be uniformly removed from the second line onwards is removed. Empty lines at the beginning and end are subsequently removed. Also, all tabs are expanded to spaces.
(From the docs link above)
Hope that helps anyone.