appveyor: guard against crash-build with VS2008

[vszakats]

The combination of -DDEBUGBUILD, a shared curl.exe, and the VS2008
compiler creates a curl.exe segfaulting on startup:

+ _bld/src/curl.exe --version
./appveyor.sh: line 122:   793 Segmentation fault      "${curl}" --version
Command exited with code 139

Ref: https://ci.appveyor.com/project/curlorg/curl/builds/49817266/job/651iy6qn1e238pqj#L191

Add job that triggers the issue and add the necessary logic to skip
running the affected curl.exe.

Ref: #13592
Closes #13654

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Fixing the actual problem would be nicer, but it would require a local
environment like the affected one and a will/need to track this down.