docs: Remove build command from agent instructions

[runningcode]

📜 Description

Remove the "Build entire project" command (./gradlew build) from the Essential Commands section of AGENTS.md.

💡 Motivation and Context

./gradlew build is an expensive full-project build that isn't needed as part of the documented agent workflow — ./gradlew check already covers running tests and the linter. Removing it keeps the agent instructions lean and avoids steering agents toward a slow, unnecessary step.

💚 How did you test it?

Docs-only change to AGENTS.md. Spotless only targets .java/.kt/*.gradle.kts, so no formatting is affected and there is no API change.

📝 Checklist

• No breaking change or entry added to the changelog.

🔮 Next steps

#skip-changelog

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.51.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[sentry]

Bug: The AGENTS.md documentation omits the necessary ./gradlew build command, leading to an incomplete development setup as the project will not be compiled.
_{Severity: MEDIUM}

Suggested Fix

Restore the ./gradlew build command to the AGENTS.md file. The build task is not redundant; it compiles the project and generates artifacts, which the check task does not. The project's Makefile confirms that build is a required step in the workflow.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: AGENTS.md#L37

Potential issue: The removal of the `./gradlew build` command from the `AGENTS.md`
documentation file is problematic. While the remaining `./gradlew check` command runs
tests and linters, it does not compile the project or produce necessary build artifacts.
The project's `Makefile` still contains a `compile` target that executes `./gradlew
build`, indicating this command is an essential part of the development workflow. A
contributor following the updated instructions will have an incomplete development setup
because the project will not be compiled, which can lead to subsequent errors and
confusion.

_{Did we get this right? 👍 / 👎 to inform future reviews.}