chore(info.xml): canonicalize PHP min, NC version range, licence spelling (#136)

Aligns appinfo/info.xml with the fleet canonical:

- <php min-version="8.3"> — matches the
  composer require.php constraint (^8.3 fleet-wide)
- <nextcloud min-version="28" max-version="34">
  — converge the fleet on one NC support range
- <licence>agpl</licence> — fix the casing/value drift
  (fleet had agpl / eupl / EUPL-1.2 / AGPL-3.0-or-later — 4 spellings).
  Stays on "agpl" workaround per the EUPL store-listing pattern;
  switch to "EUPL-1.2" once NC 34 is the fleet floor
  (ConductionNL/.github#98).

Per-app fields (<id>, <name>, <description>, <version>, etc.) are
preserved.

Drift surfaced in
https://github.com/ConductionNL/nextcloud-app-template/blob/development/docs/fleet-drift-deeper.md#4-appinfoinfoxml--significant-drift

Author: rubenvdlinde

appinfo/info.xml

@@ -41,7 +41,7 @@ Vrij en open source onder de EUPL-1.2-licentie.
 
     <dependencies>
         <nextcloud min-version="28" max-version="34"/>
-        <php min-version="8.1"/>
+        <php min-version="8.3"/>
     </dependencies>
 
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