Proposed commit message

This PR introduces a new type:

type FIPSAwareInput interface {
    IsFIPSCapable() bool
}

Filebeat inputs that wish to report if they are FIPS-capable (or not) are expected to implement this interface. Inputs that do not implement this interface are considered to be FIPS-capable.

For inputs that implement the above interface, FIPS-capable builds of Filebeat will check the input's FIPS-capability. If the input is not FIPS-capable, the input will fail to start with an error message and Filebeat will exit, e.g.:

{"log.level":"error","@timestamp":"2025-06-23T23:50:39.852-0700","log.origin":{"function":"github.com/elastic/beats/v7/libbeat/cmd/instance.handleError","file.name":"instance/beat.go","file.line":1355},"message":"Exiting: Failed to start crawler: starting input failed: input o365audit is not FIPS capable","service.name":"filebeat","ecs.version":"1.6.0"}
Exiting: Failed to start crawler: starting input failed: input o365audit is not FIPS capable

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Disruptive User Impact

None; the changes in this PR merely allow for Filebeat modules to be excluded from FIPS-capable Filebeat artifacts; there are no modules being excluded in this PR.

How to test this PR locally

$ mage clean && FIPS=true mage build
$ cat <<EOF > filebeat-test.yml
filebeat.inputs:
- type: o365audit
  id: id-nofips
  enabled: true
  application_id: foo
  tenant_id: bar
  client_secret: qux

output.console:
  enabled: true
EOF
$ ./filebeat -c ./filebeat-test.yml -e
```<hr>This is an automatic backport of pull request #44920 done by [Mergify](https://mergify.com).