Remove a dead case pattern in common.sh (SC2221/SC2222) (#4605)

resolve_template_content() rejects unsafe manifest paths with
`/*|*../*|../*)`. The third alternative can never match: `*../*`
already matches every string `../*` does, so shellcheck reports SC2221
(this pattern always overrides a later one) and SC2222 (this pattern
never matches). Removing it changes nothing: checked against
/etc/passwd, ../x, a/../b, ../, x/../../y, .., a/.., ..a, a..b, ./x and
templates/x.md -- every input classifies identically before and after.

These are warnings, so lint.yml's --severity=error does not see them.
This is one of the findings between the current threshold and the
tightening CONTRIBUTING.md describes.

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

Author: jzayas03

scripts/bash/common.sh

@@ -770,7 +770,7 @@ except Exception as exc:
                 local candidate=""
                 if [ -n "$manifest_file" ]; then
                     case "$manifest_file" in
-                        /*|*../*|../*) manifest_file="" ;;
+                        /*|*../*) manifest_file="" ;;
                     esac
                 fi
                 if [ -n "$manifest_file" ]; then