chore: drop Node.js 18 support for relevant packages (#2572)

Co-authored-by: Claude <svc-devxp-claude@slack-corp.com>
Co-authored-by: Eden Zimbelman <eden.zimbelman@salesforce.com>

Author: 3 people

.changeset/drop-node18-cli-hooks.md

@@ -0,0 +1,5 @@
+---
+"@slack/cli-hooks": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-cli-test.md

@@ -0,0 +1,5 @@
+---
+"@slack/cli-test": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-logger.md

@@ -0,0 +1,5 @@
+---
+"@slack/logger": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-oauth.md

@@ -0,0 +1,5 @@
+---
+"@slack/oauth": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-socket-mode.md

@@ -0,0 +1,5 @@
+---
+"@slack/socket-mode": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-types.md

@@ -0,0 +1,5 @@
+---
+"@slack/types": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-web-api.md

@@ -0,0 +1,5 @@
+---
+"@slack/web-api": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.changeset/drop-node18-webhook.md

@@ -0,0 +1,5 @@
+---
+"@slack/webhook": major
+---
+
+Drop Node.js 18 support. The minimum supported Node.js version is now 20.

.github/workflows/ci-build.yml

@@ -19,7 +19,6 @@ jobs:
           - "ubuntu-latest"
           - "windows-latest"
         node-version:
-          - "18.x"
           - "20.x"
           - "22.x"
           - "24.x"