ci: fix Windows runner PATH casing for mise, not in cli (#25972)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cli/configssh_internal_test.go

@@ -229,15 +229,8 @@ func Test_sshConfigMatchExecEscape(t *testing.T) {
 
 			// OpenSSH processes %% escape sequences into %
 			escaped = strings.ReplaceAll(escaped, "%%", "%")
-			c := exec.Command(cmd, arg, escaped) //nolint:gosec
-			if runtime.GOOS == "windows" {
-				// Deduplicate Path/PATH env vars so cmd.exe
-				// subprocesses (like powershell.exe used for
-				// paths with spaces) resolve correctly.
-				c.Env = appendAndDedupEnv(os.Environ())
-			}
-			b, err := c.CombinedOutput()
-			require.NoError(t, err, "command output: %s", string(b))
+			b, err := exec.Command(cmd, arg, escaped).CombinedOutput() //nolint:gosec
+			require.NoError(t, err)
 			got := strings.TrimSpace(string(b))
 			require.Equal(t, "yay", got)
 		})