Dual-license under GPLv2+ after 6–7 years? Not just 4, remove BUSL

Remove the Business Source License (BUSL) — it requires the software to
become GPLv2+ compatible after 4 years, but I think that's too soon,
keeping in mind that I'd like there to be LTS versions (under the AGPL)
that will be maintained for up to 5 years. Seems better with a gap of
1–2 years between the end-of-life of LTS versions, and the GPLv2+ date?

For now, leave the GPLv2+ dual license date commented out — I should ask
someone about the exact wording?

Author: kajmagnus

LICENSE-BUSLv11.txt

@@ -306,13 +306,21 @@ That repo, squashed, is in this repo.
 License
 -----------------------------
 
-Copyright (c) 2010-2024 Kaj Magnus Lindberg and contributors.
+Copyright (c) 2010-2025 Kaj Magnus Lindberg and contributors.
 
-Talkyard is multi licensed under 1) AGPLv3 or later, see LICENSE.txt, and
-2) Business Source License v1.1, with change license GPLv2 or later, and
-change date 2029-01-01 (we bump the change date yearly,
-so it's between 4 and 5 years into the future) — see LICENSE-BUSLv1.1.txt.
-And 3) possibly other licenses.
+Talkyard is licensed under AGPLv3 or later, see LICENSE.txt.
+
+<!-- Later, add this, but first ask someone if the wording is ok:
+Starting on 2032-01-01, this specific version of Talkyard (see ./version.txt)
+is also licensed under GPLv2 or later. That is, AGPLv3+ until year 2032, thereafter
+dual licensed under AGPLv3+ and GPLv2+.
+
+Note:
+  - We try to bump the above GPLv2 date each year, so it's 6–7 years in the future.
+  - After the above GPLv2+ date, you can *not* redistribute Talkyard under GPLv2
+    — Talkyard includes Apache2 software and Apache2 is incompatible with GPLv2.
+    You can, however, after the GPLv2+ date, redistribute Talkyard under GPLv3+.
+-->
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of

README.md

@@ -39,9 +39,9 @@ if [[ ! $next_version =~ ^v0\.$year\. ]]; then
   echo
   echo "Edit  version.txt — bump the year, and reset the in-year version to 001."
   echo
-  echo "And, don't forget to bump the Business Source License change date"
-  echo "in  README.md   and  LICENSE-BUSLv11.txt,  and the copyright-up-to"
-  echo "year in  README.md.  (4 edits in total, in 3 files.)"
+  echo "And, don't forget to bump the GPLv2 change dates"
+  echo "in  README.md,  and the copyright-up-to year too."
+  echo "(4 edits in total, in 2 files.)"
   echo
   exit 1
 fi