Pin docker.elastic.co/wolfi/chainguard-base-fips Docker tag to ebfc3f1 (#126065)

This PR contains the following updates:

| Package | Update | Change | |---|---|---| |
docker.elastic.co/wolfi/chainguard-base-fips | pinDigest |  -> `ebfc3f1`
|

---

### Configuration

📅 **Schedule**: Branch creation - "after 1pm on tuesday" (UTC),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once
you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate
Bot](https://redirect.github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOS4xMDcuMCIsInVwZGF0ZWRJblZlciI6IjM5LjEwNy4wIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyI6RGVsaXZlcnkvUGFja2FnaW5nIiwiPm5vbi1pc3N1ZSIsIlRlYW06RGVsaXZlcnkiLCJhdXRvLW1lcmdlLXdpdGhvdXQtYXBwcm92YWwiXX0=-->

Author: elastic-renovate-prod[bot]

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/DockerBase.java

@@ -26,7 +26,7 @@ public enum DockerBase {
         "-wolfi",
         "apk"
     ),
-    FIPS("docker.elastic.co/wolfi/chainguard-base-fips:sha256-ebfc3f1d7dba992231747a2e05ad1b859843e81b5e676ad342859d7cf9e425a7", "-fips", "apk"),
+    FIPS("docker.elastic.co/wolfi/chainguard-base-fips:sha256-ebfc3f1d7dba992231747a2e05ad1b859843e81b5e676ad342859d7cf9e425a7@sha256:ebfc3f1d7dba992231747a2e05ad1b859843e81b5e676ad342859d7cf9e425a7", "-fips", "apk"),
     // spotless:on
     // Based on WOLFI above, with more extras. We don't set a base image because
     // we programmatically extend from the wolfi image.