Update sigstore, cosign, rekor, and go-git dependencies (#199)

* Initial plan

* Update dependencies in internal/tools: sigstore, cosign, rekor, and go-git

Co-authored-by: jsirianni <23043836+jsirianni@users.noreply.github.com>

* fix install tools

* sync go mod with internal/tools

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jsirianni <23043836+jsirianni@users.noreply.github.com>
Co-authored-by: Joe Sirianni <joe.sirianni@observiq.com>

Author: Copilot

go.mod

@@ -1,6 +1,6 @@
 module github.com/observiq/terraform-provider-bindplane
 
-go 1.25.3
+go 1.25.5
 
 require (
 	github.com/hashicorp/go-version v1.7.0