links to documentation generated with sphinx-apidoc no longer work

Describe the bug

context When I

use sphinx-apidoc to create API documents for a Python project, e.g.:
```
sphinx-apidoc -f --module-first -o source/ my_python_package_dir
```
place links to anchors within those API documents, e.g. within my_manual_page.md, place:
```
[MyClass](../source/my_python_package.html#my_python_package.my_module.MyClass)
```

expectation I expected documentation to be built correctly, no errors, and for the generated HTML file from my_manual_page.md to have a link to the documentation for MyClass.

That worked fine through version 0.16.x of myst-parser

bug But instead I get a "reference target not found" warning, like:

Warning, treated as error:
my_manual_page.md:123:'myst' reference target not found: ../source/my_python_package.html#my_python_package.my_module.MyClass

problem This is a problem since there no longer seems to be any way to include links to sphinx-apidoc generated documentation. Note that this seems to occur even if anchors to a specific module/class are not included in the link.

I imagine that this might be related to the breaking changes announced for v0.17.0, but the fixes recommended in the breaking-change announcement did not work for me; the only solution was to roll back to v0.16.x. The closest thing to a fix was to set myst_all_links_external = True, but then that breaks links to other non-html local documentation files (e.g. *.md files).

Reproduce the bug

see above under context

List your environment

MacOS 12.4
python 3.8.7
sphinx 4.5.0
myst-parser 0.17.2 (works fine with 0.16.1)

executablebooks / MyST-Parser