Simplify pam_umask sed pattern for better robustness

Co-authored-by: kurowski <7466+kurowski@users.noreply.github.com>

Author: Copilot

Dockerfile

@@ -2,8 +2,8 @@ FROM mcr.microsoft.com/devcontainers/php:8.3
 
 # Change default umask and add user to web group so we can share write permission on web files
 # Configure pam_umask to set umask to 002 (works regardless of /etc/login.defs content)
-RUN sed -i 's/session optional\s*pam_umask.so$/session optional\t\t\tpam_umask.so umask=002/' /etc/pam.d/common-session \
-    && sed -i 's/session optional\s*pam_umask.so$/session optional\t\t\tpam_umask.so umask=002/' /etc/pam.d/common-session-noninteractive
+RUN sed -i 's/pam_umask\.so/pam_umask.so umask=002/' /etc/pam.d/common-session \
+    && sed -i 's/pam_umask\.so/pam_umask.so umask=002/' /etc/pam.d/common-session-noninteractive
 RUN usermod -aG www-data vscode
 
 # Add glow for formatting command usage output (and because it's just nice)