Below answer is based on gradle OWASP plugin version 7.4.4.

Below in my build.gradle

id "org.owasp.dependencycheck" version "7.4.4"

And below is the task configuration

dependencyCheck {
    formats = ['xml','json']
    failBuildOnCVSS = 8
    failOnError = true
    suppressionFile = 'config/dependency-check/suppressions.xml'
    check.dependsOn(dependencyCheckAnalyze)
}

And as you see we have provided a path to suppressionFile where we can define the suppression for vulnerabilities.

So, in my case our sonar build was failing due to

Filename: spring-security-oauth2-client-5.6.3.jar | Reference: CVE-2022-22978 | CVSS Score: 9.8

Filename: snakeyaml-1.33.jar | Reference: CVE-2022-1471 | CVSS Score: 9.8

So, I have added them in Suppression.xml and my file looks like below

<?xml version="1.0" encoding="UTF-8"?>
<suppressions xmlns="https://jeremylong.github.io/DependencyCheck/dependency-suppression.1.3.xsd">
    <suppress until="2023-06-01Z">
        <notes><![CDATA[
        This suppresses a CVE from SnakeYaml as it needs to wait until SpringBoot 3 upgrade
        ]]></notes>
        <packageUrl regex="true">^pkg:maven/org\.yaml/snakeyaml@.*$</packageUrl>
        <vulnerabilityName>CVE-2022-1471</vulnerabilityName>
    </suppress>
    <suppress until="2023-06-01Z">
        <notes><![CDATA[
        This suppresses a CVE from OAuth Client as it needs to wait until SpringBoot 3 upgrade
        ]]></notes>
        <packageUrl regex="true">^pkg:maven/org\.springframework\.security/spring\-security\-oauth2\-client@.*$</packageUrl>
        <vulnerabilityName>CVE-2022-22978</vulnerabilityName>
    </suppress>
</suppressions>

I recommend to use until="2023-06-01Z" so you don't suppress them forever.

Vulnerabilities can be suppressed in number of different combinations. So, please refer https://jeremylong.github.io/DependencyCheck/general/suppression.html and decide which option suits your requirement.