Bump org.postgresql:postgresql from 42.7.5 to 42.7.6

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from 42.7.5 to 42.7.6.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](https://github.com/pgjdbc/pgjdbc/compare/REL42.7.5...REL42.7.6)

---
updated-dependencies:
- dependency-name: org.postgresql:postgresql
  dependency-version: 42.7.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

proprietary/build.gradle

@@ -25,7 +25,7 @@ dependencies {
     api 'io.micrometer:micrometer-registry-prometheus'
     implementation 'com.unboundid.product.scim2:scim2-sdk-client:2.3.5'
     runtimeOnly 'com.h2database:h2:2.3.232' // Don't upgrade h2database
-    runtimeOnly 'org.postgresql:postgresql:42.7.5'
+    runtimeOnly 'org.postgresql:postgresql:42.7.6'
     constraints {
         implementation "org.opensaml:opensaml-core:$openSamlVersion"
         implementation "org.opensaml:opensaml-saml-api:$openSamlVersion"