fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN12-EXPAT-6227597
- https://snyk.io/vuln/SNYK-DEBIAN12-EXPAT-6227603
- https://snyk.io/vuln/SNYK-DEBIAN12-ZLIB-6008963
- https://snyk.io/vuln/SNYK-DEBIAN12-COREUTILS-1543939
- https://snyk.io/vuln/SNYK-DEBIAN12-COREUTILS-1543947

Dockerfile

@@ -1,5 +1,5 @@
 # Keep image in sync with scripts/update-pipfile-lock/Dockerfile
-FROM python:3.10-slim as build
+FROM python:3.13-slim as build
 
 LABEL maintainer="GitGuardian SRE Team <[email protected]>"