docs(serverless): clarify UpdateContainer and UpdateFunction behavior (#2347)

Co-authored-by: Jonathan R. <[email protected]>

Author: scaleway-bot

packages_generated/container/src/v1beta1/types.gen.ts

@@ -1282,7 +1282,18 @@ export type UpdateContainerRequest = {
    */
   port?: number
   /**
-   * Secret environment variables of the container.
+   * During an update, secret environment variables that are not specified in this field will be kept unchanged.
+
+In order to delete a specific secret environment variable, you must reference its key, but not provide any value for it.
+For example, the following payload will delete the `TO_DELETE` secret environment variable:
+
+```json
+{
+  "secret_environment_variables":[
+    {"key":"TO_DELETE"}
+  ]
+}
+```.
    */
   secretEnvironmentVariables?: Secret[]
   /**

packages_generated/function/src/v1beta1/types.gen.ts

@@ -1281,7 +1281,18 @@ export type UpdateFunctionRequest = {
    */
   description?: string
   /**
-   * Secret environment variables of the function.
+   * During an update, secret environment variables that are not specified in this field will be kept unchanged.
+
+In order to delete a specific secret environment variable, you must reference its key, but not provide any value for it.
+For example, the following payload will delete the `TO_DELETE` secret environment variable:
+
+```json
+{
+ "secret_environment_variables":[
+   {"key":"TO_DELETE"}
+ ]
+}
+```.
    */
   secretEnvironmentVariables?: Secret[]
   /**