This subcommand allows migrating and syncing secrets from the Cloud Run style
definition (multiple uppercase secrets, each with a `value` key) to the
Kubernetes style (single `env-vars` secret, each key is an environment
variable).

Two flags are available:

- `--dry-run` – when enabled, no writes will be performed and a summary of the
  skipped action is printed instead.
- `--authoritative` – when enabled, environment variables existing in the
  Kubernetes service but not the Cloud Run service will be removed. Default
  behavior is to merge the secret keys.

Also point users at the Vault usage documentation if requesting the
authorization URL fails.

Co-authored-by: Pierre Guinoiseau <pguinoiseau@gitlab.com>

Co-authored-by: Pierre Guinoiseau <pguinoiseau@gitlab.com>

The `socks5Proxy` function only installs a proxy handler, if the
`VAULT_PROXY_ADDR` environment variable is set. This allows us to test the
`migrate vault-secrets` command end-to-end, starting with flags and positional
arguments.

feat: Add the new `migrate vault-secrets` subcommand.

See merge request !1212

chore(deps): update dependency checkov to v3.2.470

See merge request !1215

chore(deps): update dependency yq to v4.47.2

See merge request !1217

chore(deps): update otel/opentelemetry-collector-contrib docker tag to v0.135.0

See merge request !1222

fix(deps): update module google.golang.org/grpc to v1.75.1

See merge request !1220

fix(deps): update googlecloud-go-sdk

See merge request !1224

fix(deps): update module github.com/fatih/color to v1.18.0

See merge request !1225

fix(deps): update module gitlab.com/gitlab-org/api/client-go to v0.144.1

See merge request !1226

fix(deps): update module golang.org/x/oauth2 to v0.31.0

See merge request !1227

chore(deps): update dependency terraform to v1.13.2

See merge request !1216

chore(deps): update terraform cloudflare to v4.52.4

See merge request !1218

chore(deps): update dependency helm to v3.19.0

See merge request !1221

chore(deps): update terraform-provider-google to v6.49.3

See merge request !1219

chore(deps): update terraform vault to v5.3.0

See merge request !1223

chore(deps): update alpine/helm docker tag to v3.19.0

See merge request !1228

chore(deps): update registry.gitlab.com/gitlab-org/cli docker tag to v1.71.2

See merge request !1229

fix(deps): update module gitlab.com/gitlab-org/api/client-go to v0.145.0

See merge request !1230

fix: reflect changes to variables in otel-config file

See merge request !1231