The following should install Tk on SP-5.40.0 and earlier:

cpanm https://github.com/StrawberryPerl/Perl-Dist-Strawberry/releases/
+download/patched_cpan_modules/Tk-804.036_001.tar.gz
[download]

For SP-5.42.0, you'll need to run:

cpanm https://github.com/StrawberryPerl/Perl-Dist-Strawberry/releases/
+download/patched_cpan_modules/Tk-804.036_001.tar.gz --configure-args=
+"OPTIMIZE=-Os"
[download]

If any tests fail, you'll need to use force - but all tests should pass, anyway.
If any tests do fail, please report back.

UPDATE:
And, for future, questions regarding Strawberry Perl issues should be addressed to either:
https://github.com/StrawberryPerl/Perl-Dist-Strawberry/issues
or
https://github.com/StrawberryPerl/Perl-Dist-Strawberry/discussions

That way, one gets to ask for (and receive) assistance in a user-friendly way without the requester (and/or responder) having to endure this generally unusable perlmonks platform.

Cheers,
Rob