meson: stop linking libcurl into all executables

We set up libcurl via the `libgit_dependencies` variable, which gets
propagated into every user of the `libgit` dependency. This is not
necessary though, as most of our executables aren't even supposed to
link against libcurl.

Fix this by only propagating include directories as a libgit dependency
and propagating the full curl dependency via `libgit_curl`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

meson.build

@@ -927,7 +927,9 @@ if curl.found()
     use_curl_for_imap_send = true
   endif
 
-  libgit_dependencies += curl
+  # Most executables don't have to link against libcurl, but we still need its
+  # include directories so that we can resolve LIBCURL_VERSION in "help.c".
+  libgit_dependencies += curl.partial_dependency(includes: true)
   libgit_c_args += '-DCURL_DISABLE_TYPECHECK'
   build_options_config.set('NO_CURL', '')
 else
@@ -1666,7 +1668,7 @@ if get_option('curl').enabled()
       'http.c',
       'http-walker.c',
     ],
-    dependencies: [libgit_commonmain],
+    dependencies: [libgit_commonmain, curl],
   )
 
   test_dependencies += executable('git-remote-http',