Bump fpsak-tidsserie from 2.6.7 to 2.6.8 (#417)

Bumps [fpsak-tidsserie](https://github.com/navikt/fp-tidsserie) from 2.6.7 to 2.6.8.
- [Release notes](https://github.com/navikt/fp-tidsserie/releases)
- [Changelog](https://github.com/navikt/fp-tidsserie/blob/master/release.properties)
- [Commits](navikt/fp-tidsserie@2.6.7...2.6.8)

---
updated-dependencies:
- dependency-name: no.nav.fpsak.tidsserie:fpsak-tidsserie
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -109,7 +109,7 @@
         <dependency>
             <groupId>no.nav.fpsak.tidsserie</groupId>
             <artifactId>fpsak-tidsserie</artifactId>
-            <version>2.6.7</version>
+            <version>2.6.8</version>
         </dependency>
     </dependencies>