chore(deps): bump securesystemslib from 1.3.0 to 1.3.1

Bumps [securesystemslib](https://github.com/secure-systems-lab/securesystemslib) from 1.3.0 to 1.3.1.
- [Release notes](https://github.com/secure-systems-lab/securesystemslib/releases)
- [Changelog](https://github.com/secure-systems-lab/securesystemslib/blob/main/CHANGELOG.md)
- [Commits](secure-systems-lab/securesystemslib@v1.3.0...v1.3.1)

---
updated-dependencies:
- dependency-name: securesystemslib
  dependency-version: 1.3.1
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/main.txt

@@ -2327,9 +2327,9 @@ s3transfer==0.11.5 \
     --hash=sha256:757af0f2ac150d3c75bc4177a32355c3862a98d20447b69a0161812992fe0bd4 \
     --hash=sha256:8c8aad92784779ab8688a61aefff3e28e9ebdce43142808eaa3f0b0f402f68b7
     # via boto3
-securesystemslib==1.3.0 \
-    --hash=sha256:5b53e5989289d97fa42ed7fde1b4bad80985f15dba8c774c043b395a90c908e5 \
-    --hash=sha256:8cbb277513444d9828016fe09eaa4a6fe25468e4bf411995c0542c6d2102af83
+securesystemslib==1.3.1 \
+    --hash=sha256:2e5414bbdde33155a91805b295cbedc4ae3f12b48dccc63e1089093537f43c81 \
+    --hash=sha256:ca915f4b88209bb5450ac05426b859d74b7cd1421cafcf73b8dd3418a0b17486
     # via tuf
 sentry-sdk==2.39.0 \
     --hash=sha256:8c185854d111f47f329ab6bc35993f28f7a6b7114db64aa426b326998cfa14e9 \