Expose GKE desired_emulated_version update trigger in Cluster resource

[ChinemeremChigbo]

Exposes GKE support for declaratively completing GKE rollback-safe minor control plane upgrades in the google-beta provider:

• desired_emulated_version (Optional): Write-only trigger field (no flattener) to complete upgrades.
• emulated_version (Computed): Read-only status field returning the active emulated version.
• Testing: Added E2E acceptance test TestAccContainerCluster_desiredEmulatedVersion (3-step soak upgrade) with live GKE REST API validation.

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Release Note Template for Downstream PRs (will be copied)

container: added `desired_emulated_version` and `emulated_version` fields to `google_container_cluster` resource (beta)

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes for commit 90e73c2:

Diff report

Your PR generated the following diffs in downstream repositories:

Repository	Diff Link	Changes
google provider	View Diff	1 file changed, 150 insertions(+)
google-beta provider	View Diff	2 files changed, 180 insertions(+)
terraform-google-conversion	View Diff	1 file changed, 3 insertions(+)

Errors

google-beta provider:

• The diff processor failed to build. This is usually due to the downstream provider failing to compile.

Step 1: Replaying Mode

Caution

Build Failure during VCR tests

🔴 REPLAYING mode: The following packages failed to build:

• container

Please fix the compilation errors to complete your PR.

View the build log

@ChinemeremChigbo VCR tests complete for 90e73c2!

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes for commit 06637fa:

Diff report

Your PR generated the following diffs in downstream repositories:

Repository	Diff Link	Changes
google provider	View Diff	1 file changed, 150 insertions(+)
google-beta provider	View Diff	2 files changed, 180 insertions(+)
terraform-google-conversion	View Diff	1 file changed, 3 insertions(+)

Errors

google-beta provider:

• The diff processor failed to build. This is usually due to the downstream provider failing to compile.

Step 1: Replaying Mode

Caution

Build Failure during VCR tests

🔴 REPLAYING mode: The following packages failed to build:

• container

Please fix the compilation errors to complete your PR.

View the build log

@ChinemeremChigbo VCR tests complete for 06637fa!