chore(Dockerfile): update CryptPad base image from 2025.3.0 to 2025.6.0

Author: gcordalis

Dockerfile

@@ -1,4 +1,4 @@
-FROM cryptpad/cryptpad:version-2025.3.0
+FROM cryptpad/cryptpad:version-2025.6.0
 
 # Switch to the cryptpad user for remaining operations
 USER cryptpad
@@ -8,4 +8,4 @@ WORKDIR /cryptpad/lib/plugins
 RUN git clone https://github.com/cryptpad/sso/
 
 # Revert working directory to the root of the cryptpad project
-WORKDIR /cryptpad
+WORKDIR /cryptpad