docs: remove snyk

Snyk has issues with npm 7 and because the project
is using renovate it is receiving fixes as soon
as they are released.

Issues with npm 7 are mostly seen in large projects
where it incorrectly reports an
outdated package-lock.json causing the build to
fail.

Author: coderbyheart

.mergify.yml

@@ -1,8 +1,7 @@
 pull_request_rules:
   - name: Automatic merge security PRs when all status checks pass
     conditions:
-      - author~=^(snyk-bot|dependabot\[bot\]|renovate\[bot\])$
-      - status-success=security/snyk (Asset Tracker Cloud)
+      - author~=^(dependabot\[bot\]|renovate\[bot\])$
     actions:
       merge:
         method: rebase

.snyk

@@ -1,7 +1,6 @@
 # TypeScript ESLint Config [![npm version](https://img.shields.io/npm/v/@nordicsemiconductor/eslint-config-asset-tracker-cloud-typescript.svg)](https://www.npmjs.com/package/@nordicsemiconductor/eslint-config-asset-tracker-cloud-typescript)
 
 [![GitHub Actions](https://github.com/NordicSemiconductor/asset-tracker-cloud-eslint-config-typescript/workflows/Semantic%20Release/badge.svg)](https://github.com/NordicSemiconductor/asset-tracker-cloud-eslint-config-typescript/actions)
-[![Known Vulnerabilities](https://snyk.io/test/github/NordicSemiconductor/asset-tracker-cloud-eslint-config-typescript/badge.svg?targetFile=package.json)](https://snyk.io/test/github/NordicSemiconductor/asset-tracker-cloud-eslint-config-typescript?targetFile=package.json)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 [![Renovate](https://img.shields.io/badge/renovate-enabled-brightgreen.svg)](https://renovatebot.com)
 [![Mergify Status](https://img.shields.io/endpoint.svg?url=https://gh.mergify.io/badges/NordicSemiconductor/asset-tracker-cloud-eslint-config-typescript)](https://mergify.io)