curl and libcurl 8.15.0

 Public curl releases:         269
 Command line options:         269
 curl_easy_setopt() options:   308
 Public functions in libcurl:  96
 Contributors:                 3432

This release includes the following changes:

 o TLS: remove support for Secure Transport and BearSSL [19]

This release includes the following bugfixes:

 o build: assume `sys/socket.h`, `sys/time.h` on non-Windows (as in `curl/curl.h`) [21]
 o cmake: document OpenSSL and ngtcp2 crypto lib custom variables [29]
 o cmake: drop never propagated C macros [22]
 o cmake: replace `cmakelint` with `cmake-lint` from `cmakelang`, fix issues [20]
 o curl.h: make CURLSSLOPT_* symbols defined as longs [3]
 o curl.h: remove the "RESERVED" error codes [2]
 o curl_path: make SFTP handle a path like /~ properly. [11]
 o docs/examples: add ftp-delete.c [5]
 o INSTALL.md: cygwin details and add source code link [4]
 o libssh: de-complex myssh_statemach_act() [18]
 o pingpong: on disconnect, check for unflushed pingpong state [12]
 o pytest: adapt for runs with openssl-1.1.1
 o pytest: disable test_07_37 and test_07_36 with openssl's quic [1]
 o RELEASE-PROCEDURE.md: update docs/VERSIONS [7]
 o schannel: drop Windows 2000 compatibility logic [26]
 o SCP/SFTP: avoid busy loop after EAGAIN [8]
 o system.h: remove some macros [6]
 o test1117: reduce write delays [9]
 o tests/servers.pm: add more ways to figure out current user [17]
 o tests: drop mk-bundle exceptions [25]
 o tests: fail torture if !valgrind&threaded resolver [31]
 o tests: torture: don't duplicate valgrind command [32]
 o tool_getparam: fix --ftp-pasv [15]
 o tool_operate: fix return code when --retry is used but not triggered [13]
 o url: fix connection lifetime checks [14]
 o urlapi: simplify and split into sub functions [16]
 o vauth: move auth structs to conn meta data [30]
 o windows: reduce/stop loading DLLs at runtime [27]

This release includes the following known bugs:

 See https://curl.se/docs/knownbugs.html

For all changes ever done in curl:

 See https://curl.se/changes.html

Planned upcoming removals include:

 o Support for the msh3 HTTP/3 backend
 o Supporting curl builds using VS2008
 o The winbuild build system
 o Windows CE support

 See https://curl.se/dev/deprecate.html

This release would not have looked like this without help, code, reports and
advice from friends like these:

  Carlos Henrique Lima Melara, Christian Weisgerber, Dan Fandrich,
  Daniel Stenberg, fjaell on github, John Haugabook, Orgad Shaneh, Ray Satiro,
  renovate[bot], Stefan Eissing, Viktor Szakats, Yedaya Katsman
  (12 contributors)

References to bug reports and discussions on issues:

 [1] = https://curl.se/bug/?i=17539
 [2] = https://curl.se/bug/?i=17563
 [3] = https://curl.se/bug/?i=17535
 [4] = https://curl.se/bug/?i=17485
 [5] = https://curl.se/bug/?i=17540
 [6] = https://curl.se/bug/?i=17498
 [7] = https://curl.se/bug/?i=17584
 [8] = https://curl.se/bug/?i=17533
 [9] = https://curl.se/bug/?i=17530
 [11] = https://curl.se/bug/?i=17534
 [12] = https://curl.se/bug/?i=17555
 [13] = https://curl.se/bug/?i=17554
 [14] = https://curl.se/bug/?i=17571
 [15] = https://curl.se/bug/?i=17545
 [16] = https://curl.se/bug/?i=17565
 [17] = https://curl.se/bug/?i=17544
 [18] = https://curl.se/bug/?i=17573
 [19] = https://curl.se/bug/?i=16677
 [20] = https://curl.se/bug/?i=17576
 [21] = https://curl.se/bug/?i=17522
 [22] = https://curl.se/bug/?i=17580
 [25] = https://curl.se/bug/?i=17468
 [26] = https://curl.se/bug/?i=17447
 [27] = https://curl.se/bug/?i=17413
 [29] = https://curl.se/bug/?i=17574
 [30] = https://curl.se/bug/?i=17557
 [31] = https://curl.se/bug/?i=17501
 [32] = https://curl.se/bug/?i=17501