[azmetrics] add fake support

[gracewilcox]

Closes #24307

• Add fake support for the azmetrics package
• Regenerated with latest autorest codegen version

[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

sdk/monitor/query/azmetrics

[Copilot]

Pull Request Overview

This PR adds fake support for the azmetrics package by introducing fake server transport implementations and updating generated code. Key changes include:

• Adding fake implementations for time formatting and querying through new files in the fake package.
• Updating and reordering query parameter assignments in the client request creation.
• Upgrading autorest configuration with the new codegen version and enabling the generation of fakes.

Reviewed Changes

Copilot reviewed 20 out of 22 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
sdk/monitor/query/azmetrics/fake/time_rfc3339.go	Adds fake time parsing support with updated regex/layouts.
sdk/monitor/query/azmetrics/fake/server_test.go	Adds tests to validate the behavior of the fake server.
sdk/monitor/query/azmetrics/fake/server.go	Implements fake server transport and dispatch for queries.
sdk/monitor/query/azmetrics/time_rfc3339.go	Updates time parsing logic and removes build constraint tags.
sdk/monitor/query/azmetrics/autorest.md	Updates module version, autorest codegen version, and enables fake generation.
Other generated files	Removes go:build tags to streamline build configuration.

Files not reviewed (2)

• eng/config.json: Language not supported
• sdk/monitor/query/azmetrics/go.mod: Language not supported

Comments suppressed due to low confidence (2)

sdk/monitor/query/azmetrics/fake/time_rfc3339.go:43

• Ensure tests cover a variety of date-time string formats (with or without 'T', timezone offsets, etc.) to verify the regex and layout selection logic in UnmarshalJSON.

func (t *dateTimeRFC3339) UnmarshalJSON(data []byte) error {

sdk/monitor/query/azmetrics/client.go:39

• Verify that the reordering of query parameter assignments in queryResourcesCreateRequest maintains the intended behavior of the API call, ensuring that all required parameters are set appropriately.

ctx = context.WithValue(ctx, runtime.CtxAPINameKey{}, operationName)