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

tests/http/clients/.gitignore

@@ -2,12 +2,4 @@
 #
 # SPDX-License-Identifier: curl
 
-h2-serverpush
-hx-download
-hx-upload
-ws-data
-ws-pingpong
-h2-upgrade-extreme
-tls-session-reuse
-h2-pausing
-upload-pausing
+/[0-9a-z_-]+

tests/http/clients/Makefile.inc

@@ -24,11 +24,11 @@
 
 # These are all libcurl example programs to be test compiled
 check_PROGRAMS = \
-  hx-download \
-  hx-upload \
   h2-pausing \
   h2-serverpush \
   h2-upgrade-extreme \
+  hx-download \
+  hx-upload \
   tls-session-reuse \
   upload-pausing \
   ws-data \