ci(fetch-commits): fix sed regex for tag extraction

The regex for stripping the suffix from tag references was incorrectly escaped. The backslashes were being interpreted as literal characters by the sed command. Remove the extra escaping to correctly match the `^{}` suffix pattern.

.github/actions/fetch-commits/action.yml

@@ -41,7 +41,7 @@ runs:
           repo="$1"
           commit="$2"
           git ls-remote --tags "$repo" | awk -v c="$commit" '$1==c && $2 ~ /^refs\/tags\// {print $2}' \
-            | sed -E 's#^refs/tags/##; s#\\^\\{\\}\\$##' \
+            | sed -E 's#^refs/tags/##; s#\^\{\}$##' \
             | sort -V \
             | tail -n 1
         }