Fix advice string bug in validate_issue_format()

- Fixed f-string typo: "by with" → "with"
- Fixed object interpolation: use self.article_issue.issue (string) instead of self.article_issue (object)
- Fixed template: removed </issue> closing tag from advice string
- Advice now correctly displays: "Replace {issue_value} in <article-meta><issue> with one of {expected}"

Co-authored-by: robertatakenaka <505143+robertatakenaka@users.noreply.github.com>

Author: Copilot

packtools/sps/validation/front_articlemeta_issue.py

@@ -185,7 +185,7 @@ def validate_issue_format(self):
                 expected=expected,
                 obtained=parsed_issue,
                 advice=(
-                    f"""Replace {self.article_issue} in <article-meta><issue>{self.article_issue}</issue> by with one of {expected}"""
+                    f"Replace {self.article_issue.issue} in <article-meta><issue> with one of {expected}"
                     if not got_valid_format
                     else None
                 ),