"installed" attribute in .phive/phars.xml is not updated after tool downgrade

[sebastianbergmann]

$ phive --version 
Phive 0.14.4 - Copyright (C) 2015-2020 by Arne Blankerts, Sebastian Heuer and Contributors

.phive/phars.xml

<?xml version="1.0" encoding="UTF-8"?>
<phive xmlns="https://phar.io/phive">
  <phar name="phpab" version="^1.25" installed="1.26.0" location="./tools/phpab" copy="true"/>
  <phar name="php-cs-fixer" version="^2.16" installed="2.16.7" location="./tools/php-cs-fixer" copy="true"/>
  <phar name="phpdox" version="^0.12" installed="0.12.0" location="./tools/phpdox" copy="true"/>
  <phar name="phploc" version="^4.0" installed="4.0.1" location="./tools/phploc" copy="true"/>
  <phar name="psalm" version="^4.0" installed="4.0.1" location="./tools/psalm" copy="true"/>
  <phar name="humbug/php-scoper" version="^0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>
  <phar name="roave/backwardcompatibilitycheck" version="^5.0.0" installed="5.0.0" location="./tools/roave-backward-compatibility-check" copy="true"/>
  <phar name="composer" version="^2.0.3" installed="2.0.3" location="./tools/composer" copy="true"/>
</phive>

$ ./tools/php-scoper --version
PHP Scoper version 0.13.5 2020-09-16 13:19:21 UTC

When I make this change by editing .phive/phars.xml ...

diff --git a/.phive/phars.xml b/.phive/phars.xml
index 89d5efeb3..3d7fb29cf 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -5,7 +5,7 @@
   <phar name="phpdox" version="^0.12" installed="0.12.0" location="./tools/phpdox" copy="true"/>
   <phar name="phploc" version="^4.0" installed="4.0.1" location="./tools/phploc" copy="true"/>
   <phar name="psalm" version="^4.0" installed="4.0.1" location="./tools/psalm" copy="true"/>
-  <phar name="humbug/php-scoper" version="^0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>
+  <phar name="humbug/php-scoper" version="0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>

... and then update ...

$ phive update --force-accept-unsigned
Phive 0.14.4 - Copyright (C) 2015-2020 by Arne Blankerts, Sebastian Heuer and Contributors
Copying phpab-1.26.0.phar to /usr/local/src/phpunit/tools/phpab
Copying php-cs-fixer-2.16.7.phar to /usr/local/src/phpunit/tools/php-cs-fixer
Copying phpdox-0.12.0.phar to /usr/local/src/phpunit/tools/phpdox
Copying phploc-4.0.1.phar to /usr/local/src/phpunit/tools/phploc
Copying psalm-4.0.1.phar to /usr/local/src/phpunit/tools/psalm
Downloading https://api.github.com/rate_limit
Copying php-scoper-0.13.2.phar to /usr/local/src/phpunit/tools/php-scoper
Copying backwardcompatibilitycheck-5.0.0.phar to /usr/local/src/phpunit/tools/roave-backward-compatibility-check
Copying composer-2.0.3.phar to /usr/local/src/phpunit/tools/composer

$ ./tools/php-scoper --version
PHP Scoper version 0.13.2 2020-06-14 08:19:08 UTC

... then the installed version is not update in .phive/phars.xml:

diff --git a/.phive/phars.xml b/.phive/phars.xml
index 89d5efeb3..3d7fb29cf 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -5,7 +5,7 @@
   <phar name="phpdox" version="^0.12" installed="0.12.0" location="./tools/phpdox" copy="true"/>
   <phar name="phploc" version="^4.0" installed="4.0.1" location="./tools/phploc" copy="true"/>
   <phar name="psalm" version="^4.0" installed="4.0.1" location="./tools/psalm" copy="true"/>
-  <phar name="humbug/php-scoper" version="^0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>
+  <phar name="humbug/php-scoper" version="0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>

I would have expected instead:

diff --git a/.phive/phars.xml b/.phive/phars.xml
index 89d5efeb3..3d7fb29cf 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -5,7 +5,7 @@
   <phar name="phpdox" version="^0.12" installed="0.12.0" location="./tools/phpdox" copy="true"/>
   <phar name="phploc" version="^4.0" installed="4.0.1" location="./tools/phploc" copy="true"/>
   <phar name="psalm" version="^4.0" installed="4.0.1" location="./tools/psalm" copy="true"/>
-  <phar name="humbug/php-scoper" version="^0.13.2" installed="0.13.5" location="./tools/php-scoper" copy="true"/>
+  <phar name="humbug/php-scoper" version="0.13.2" installed="0.13.2" location="./tools/php-scoper" copy="true"/>