fix: do not use SNAPSHOT on push tags (#6)

chore: disable some platforms for now

## Description

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relates to #1234

## Checklist

- [ ] Issue was linked above
- [ ] Code format was applied: `make fmt`
- [ ] Examples were added / adjusted (see `examples/` directory)
- [x] Docs are up-to-date: `make generate-docs` (will be checked by CI)
- [ ] Unit tests got implemented or updated
- [ ] Acceptance tests got implemented or updated (see e.g. [here](f5f99d1709/stackit/internal/services/dns/dns_acc_test.go))
- [x] Unit tests are passing: `make test` (will be checked by CI)
- [x] No linter issues: `make lint` (will be checked by CI)

Reviewed-on: #6
Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>
Co-committed-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>

sample/sqlserver/sqlserver.tf

@@ -18,9 +18,9 @@
 #   value = stackit_kms_key.key.key_id
 # }
 
-resource "stackitprivatepreview_sqlserverflexalpha_instance" "sqlsrv" {
+resource "stackitprivatepreview_sqlserverflexalpha_instance" "msh-sna-001" {
   project_id      = var.project_id
-  name            = "msh-example-instance-002"
+  name            = "msh-sna-001"
   backup_schedule = "0 3 * * *"
   retention_days  = 31
   flavor_id       = data.stackitprivatepreview_sqlserverflexalpha_flavor.sqlserver_flavor.flavor_id