docs: fix reversed descriptions of version.Arch and info.Architecture

The API documentation had incorrect descriptions for these fields:

- `/version` endpoint's `Arch` field was described generically but actually
  returns the Go runtime's GOARCH value
- `/info` endpoint's `Architecture` field incorrectly stated it returns
  GOARCH, but it actually returns the OS-reported hardware architecture
  (equivalent to `uname -m`)

This commit corrects the descriptions to accurately reflect the
implementation.

Fixes #49594

Signed-off-by: majiayu000 <1835304752@qq.com>

api/swagger.yaml

@@ -6587,7 +6587,9 @@ definitions:
         example: "linux"
       Arch:
         description: |
-          The architecture that the daemon is running on
+          Architecture of the daemon, as returned by the Go runtime (`GOARCH`).
+
+          A full list of possible values can be found in the [Go documentation](https://go.dev/doc/install/source#environment).
         type: "string"
         example: "amd64"
       KernelVersion:
@@ -6814,10 +6816,13 @@ definitions:
         example: "linux"
       Architecture:
         description: |
-          Hardware architecture of the host, as returned by the Go runtime
+          Hardware architecture of the host, as returned by the operating system.
-          (`GOARCH`).
+          This is equivalent to the output of `uname -m` on Linux.
 
-          A full list of possible values can be found in the [Go documentation](https://go.dev/doc/install/source#environment).
+          Unlike `Arch` (from `/version`), this reports the machine's native
+          architecture, which can differ from the Go runtime architecture when
+          running a binary compiled for a different architecture (for example,
+          a 32-bit binary running on 64-bit hardware).
         type: "string"
         example: "x86_64"
       NCPU: