Fix regex syntax in matching os-release (#38010)

From
https://github.com/zed-industries/zed/pull/37712#issuecomment-3281970712,
thank you @zywo

Release Notes:

- N/A

script/linux

@@ -47,7 +47,7 @@ if [[ -n $apt ]]; then
     musl-dev
     build-essential
   )
-  if (grep -qP 'PRETTY_NAME="((Debian|Raspbian).+13|' /etc/os-release); then
+  if (grep -qP 'PRETTY_NAME="(Debian|Raspbian).+13' /etc/os-release); then
       # libstdc++-14-dev is in build-essential
       deps+=( mold )
   elif (grep -qP 'PRETTY_NAME="(Linux Mint 22|.+24\.(04|10))' /etc/os-release); then