test: update snapshots with corrected formatting

- Remove backslash escaping from backticks in message text
- Update diagnostic ordering to match cache_key sort order

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: psteinroe

crates/pgls_splinter/tests/snapshots/multiple_issues.snap

@@ -3,21 +3,21 @@ source: crates/pgls_splinter/tests/diagnostics.rs
 expression: content
 snapshot_kind: text
 ---
-Category: splinter/performance/unindexedForeignKeys
-Severity: Information
-Message: Table \`public.child_table\` has a foreign key \`child_table_parent_id_fkey\` without a covering index. This can lead to suboptimal query performance.
-Advices:
-Identifies foreign key constraints without a covering index, which can impact database performance.
-[Info] table: public.child_table
-{"fkey_name":"child_table_parent_id_fkey","fkey_columns":[2]}
-[Info] Remediation: https://supabase.com/docs/guides/database/database-linter?lint=0001_unindexed_foreign_keys
-
----
-
 Category: splinter/performance/noPrimaryKey
 Severity: Information
 Message: Table \`public.no_pk_table\` does not have a primary key
 Advices:
 Detects if a table does not have a primary key. Tables without a primary key can be inefficient to interact with at scale.
 [Info] table: public.no_pk_table
 [Info] Remediation: https://supabase.com/docs/guides/database/database-linter?lint=0004_no_primary_key
+
+---
+
+Category: splinter/performance/unindexedForeignKeys
+Severity: Information
+Message: Table `public.child_table` has a foreign key `child_table_parent_id_fkey` without a covering index. This can lead to suboptimal query performance.
+Advices:
+Identifies foreign key constraints without a covering index, which can impact database performance.
+[Info] table: public.child_table
+{"fkey_name":"child_table_parent_id_fkey","fkey_columns":[2]}
+[Info] Remediation: https://supabase.com/docs/guides/database/database-linter?lint=0001_unindexed_foreign_keys

crates/pgls_splinter/tests/snapshots/unindexed_foreign_key.snap

@@ -5,7 +5,7 @@ snapshot_kind: text
 ---
 Category: splinter/performance/unindexedForeignKeys
 Severity: Information
-Message: Table \`public.posts\` has a foreign key \`posts_user_id_fkey\` without a covering index. This can lead to suboptimal query performance.
+Message: Table `public.posts` has a foreign key `posts_user_id_fkey` without a covering index. This can lead to suboptimal query performance.
 Advices:
 Identifies foreign key constraints without a covering index, which can impact database performance.
 [Info] table: public.posts