Allow configuring the server project cache size (Request in QGIS)

[qgis-bot]

Request for documentation

From pull request qgis/QGIS#61332
Author: @manisandro
QGIS version: 3.44

Allow configuring the server project cache size

PR Description:

The server QgsConfigCache currently uses default-constructed QCaches which default to cost=100, i.e. 100 entries. This PR adds the QGIS_SERVER_PROJECT_CACHE_SIZE Env-Var to make this configurable.

Commits tagged with [need-docs] or [FEATURE]

[DelazJ]

https://docs.qgis.org/3.46/en/docs/server_manual/config.html#environment-variables