chore: reference envvars.upload (not import) in isSecret changeset

Author: ericallam

.changeset/envvars-import-is-secret.md

@@ -2,10 +2,10 @@
 "@trigger.dev/core": patch
 ---
 
-`envvars.import` now accepts an optional `isSecret` flag, letting you create the imported variables as secret (redacted) environment variables. When omitted, variables default to non-secret.
+`envvars.upload` now accepts an optional `isSecret` flag, letting you create the imported variables as secret (redacted) environment variables. When omitted, variables default to non-secret.
 
 ```ts
-await envvars.import("proj_1234", "prod", {
+await envvars.upload("proj_1234", "prod", {
   variables: { STRIPE_SECRET_KEY: "sk_live_..." },
   isSecret: true,
 });