misc: remove support for curl_off_t < 8 bytes

Closes #10597

docs/DEPRECATE.md

@@ -6,27 +6,6 @@ email the
 as soon as possible and explain to us why this is a problem for you and
 how your use case cannot be satisfied properly using a workaround.
 
-## Support for systems without 64 bit data types
-
-curl will *require* support for a 64 bit data type (like `long long` or an
-alternative) to build. These days, few systems are used where no such type is
-around, so it is increasingly unnecessary to spend effort and time on
-maintaining this support. Also, supporting 32 bit values for some of those
-fields is complicated and hard to test.
-
-Adding this requirement will make the code simpler, easier to maintain and the
-test coverage better. It is a low price too, since virtually no users are
-still building curl on such systems.
-
-`long long` was not a standard type until C99, but has been supported by C89
-compilers since the 1990s.
-
-Starting in 8.0.0 (March 2023), the plan is to drop support.
-
-Starting in 7.86.0, building curl with configure requires the additional flag
-`--with-n64-deprecated` if the `curl_off_t` type on your system is smaller
-than 8 bytes, in an attempt to highlight these plans to affected users.
-
 ## NSS
 
 We remove support for building curl with the NSS TLS library in August 2023.
@@ -77,3 +56,4 @@ curl will remove the support for space-separated names in July 2024.
  - axTLS
  - PolarSSL
  - NPN
+ - Support for systems without 64 bit data types