Update security scan config (and .go-version)

[tvoran]

Updates .release/security-scan.hcl to be more in line with Vault's, and relies on the OSV vulnerability database for container scans instead of just alpine_secdb/alpine_security. Updates .go-version in line with the 1.24 bump from the last dependabot update.

Scanning results:

❯ make build GOARCH=arm64 && mkdir -p dist/linux/arm64 && cp dist/vault-k8s dist/linux/arm64/ && \
    docker build --build-arg VERSION=0.0.0-dev --no-cache --target default -t docker.io/hashicorp/vault-k8s:0.0.0-dev .

❯ SECURITY_SCANNER_CONFIG_FILE=./.release/security-scan.hcl scan binary dist/vault-k8s                                           
✓ Scanned file:{path:"dist/vault-k8s"} in 5.2s - no results found

❯ SECURITY_SCANNER_CONFIG_FILE=./.release/security-scan.hcl scan container --local-daemon docker.io/hashicorp/vault-k8s:0.0.0-dev
✓ Scanned local_daemon:true registry:{host:"index.docker.io" repository:"hashicorp/vault-k8s" tag:"0.0.0-dev"} in 31.3s - no results found

[tvoran]

Thanks!