debootstrap: update to 1.0.143

debootstrap: update to 1.0.143

Update to latest upstream release.

Highlights of changes since 1.0.128:
 * Added support for Debian 13 (trixie)
 * Added support for many new Ubuntu releases (jammy through plucky)
 * Improvements to keyring handling
 * Various bug fixes and cleanups

Drop PKG_REAL_VERSION and the now-redundant PKG_BUILD_DIR override:
upstream and downstream versions match, so use PKG_VERSION directly
in PKG_SOURCE.

Link: https://salsa.debian.org/installer-team/debootstrap/-/blob/1.0.143/debian/changelog
Signed-off-by: Daniel Golle <redacted>