tools/upgrade-version updates the Change Date in LICENSE.txt

[bfops]

Description of Changes

We have sometimes missed this field when doing upgrades. This PR automates it as part of the rest of tools/upgrade-version.

Closes #2284.

API and ABI breaking changes

No runtime changes

Expected complexity level and risk

2

Testing

$ ( cd tools/upgrade-version && cargo run -- 1.2.3 ) 2>/dev/null && git diff LICENSE.txt
diff --git a/LICENSE.txt b/LICENSE.txt
index ca1f88fef..adca0d5e3 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -5,7 +5,7 @@ Business Source License 1.1
 Parameters
 
 Licensor:             Clockwork Laboratories, Inc.
-Licensed Work:        SpacetimeDB 1.2.0
+Licensed Work:        SpacetimeDB 1.2.3
                       The Licensed Work is
                       (c) 2023 Clockwork Laboratories, Inc.
                       
@@ -21,7 +21,7 @@ Additional Use Grant: You may make use of the Licensed Work provided your
                       Licensed Work by creating tables whose schemas are
                       controlled by such third parties.
 
-Change Date:          2030-06-04
+Change Date:          2030-06-24
 
 Change License:       GNU Affero General Public License v3.0 with a linking
                       exception

[bfops]

SDK Tests failing spuriously. I will re-run once the other workflows finish.

[jdetter]

I confirmed with TL that this behavior is correct. Thanks @bfops !