tidy-up: .gitignore lines mostly

- `.gitignore`: delete, dedupe and move rules upwards.
  Ref: 6389ba87b8 #13311
- `.gitignore`: fix generated test sources.
  Follow-up to 71cf0d1fca #14772
- `.gitignore`: replace exe listings with a wildcard.
- lib: move `setup-*.h` from `EXTRA_DIST` to `CURL_HFILES`.
- `makedebug.bat`: uppercase an argument to match docs.
- GHA/non-native: delete stray env.
  Follow-up to 12a6de2f66 #16043
- sort source lists.

Closes #16093

CMake/CurlTests.c

@@ -50,7 +50,6 @@ int main(void)
   int flags = 0;
   if(0 != fcntl(0, F_SETFL, flags | O_NONBLOCK))
     return 1;
-  ;
   return 0;
 }
 #endif