chore(ci): loosen approval requirement and switch to rebase merge strategy

Why this change was needed:
The project aims for faster CI/CD iteration cycles while maintaining
cleaner project history. The dual approval requirement was creating
bottlenecks for smaller changes and feature branches. Rebase merging
produces a linear, more readable history that simplifies debugging
and blame attribution.

Problem solved:
Reduced friction in the PR review process by lowering the approval
threshold, while maintaining code quality. Rebase merging eliminates
merge commits that clutter the git log and make history harder to follow.

What changed:
- Lowered approved-reviews-by threshold from 2 to 1
- Changed merge method from merge commits to rebase strategy

Author: mimi1vx

.mergify.yml

@@ -11,13 +11,13 @@ pull_request_rules:
         - "#check-pending=0"
         - linear-history
       - and:
-        - "#approved-reviews-by>=2"
+        - "#approved-reviews-by>=1"
         - "#changes-requested-reviews-by=0"
         # https://doc.mergify.io/examples.html#require-all-requested-reviews-to-be-approved
         - "#review-requested=0"
     actions: &merge
       merge:
-        method: merge
+        method: rebase
   - name: automatic merge on special label
     conditions:
       - and: *base_checks