fix: bump go directive to 1.25.7 to resolve stdlib CVEs (#926)

Go 1.25.0 is affected by CVE-2025-58183 and other Go stdlib
vulnerabilities. Bumping to 1.25.7 ensures release binaries
are compiled with a patched toolchain.

Author: willyguggenheim

go.mod

@@ -1,6 +1,6 @@
 module github.com/databus23/helm-diff/v3
 
-go 1.25.0
+go 1.25.7
 
 require (
 	github.com/Masterminds/semver/v3 v3.4.0