Python dependency: Update boto3 requirement from ==1.42.* to ==1.43.*

Updates the requirements on [boto3](https://github.com/boto/boto3) to permit the latest version.
- [Release notes](https://github.com/boto/boto3/releases)
- [Commits](boto/boto3@1.42.0...1.43.2)

---
updated-dependencies:
- dependency-name: boto3
  dependency-version: 1.43.2
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -19,7 +19,7 @@ azure-mgmt-rdbms==10.1.1
 azure-mgmt-resource==25.0.0
 azure-mgmt-subscription==3.1.1
 bcrypt==5.0.*
-boto3==1.42.*
+boto3==1.43.*
 certifi==2026.4.22
 cryptography==46.0.*
 Flask-Babel==4.0.*