DEPS bump to pull in linter 0.1.18 (#26596).

Fixes: https://github.com/dart-lang/sdk/issues/26596.

BUG=
R=brianwilkerson@google.com

Review URL: https://codereview.chromium.org/2033543004 .
diff --git a/DEPS b/DEPS
index 138d463..1b74da6 100644
--- a/DEPS
+++ b/DEPS
@@ -62,7 +62,7 @@
   "intl_rev": "@a8b480b9c436f6c0ec16730804c914bdb4e30d53",
   "jinja2_rev": "@2222b31554f03e62600cd7e383376a7c187967a1",
   "json_rpc_2_tag": "@2.0.0",
-  "linter_rev": "@8e1873ba689fbb0064cbd27c238c898106938dcd",
+  "linter_rev": "@ccd8dbf7562b7645dc8c54a578b78b38970c71d6",
   "logging_rev": "@85d83e002670545e9039ad3985f0018ab640e597",
   "markdown_rev": "@4aaadf3d940bb172e1f6285af4d2b1710d309982",
   "matcher_tag": "@0.12.0",