feat(core): Remove startTransaction export (#11015)

Instead we, for now, inline this directly into core `trace` functions,
which is the only place left where we use this.

Author: mydea

dev-packages/browser-integration-tests/suites/public-api/startSpan/basic/subject.js

@@ -3,6 +3,9 @@ async function run() {
     Sentry.startSpan({ name: 'child_span' }, () => {
       // whatever a user would do here
     });
+
+    // unfinished spans are filtered out
+    Sentry.startInactiveSpan({ name: 'span_4' });
   });
 }
 

dev-packages/browser-integration-tests/suites/public-api/startTransaction/circular_data/subject.js renamed to dev-packages/browser-integration-tests/suites/public-api/startSpan/circular_data/subject.js

@@ -1,4 +1,7 @@
-const transaction = Sentry.startTransaction({ name: 'some_transaction' });
+const transaction = Sentry.startInactiveSpan({
+  name: 'some_transaction',
+  forceTransaction: true,
+});
 
 transaction.setMeasurement('metric.foo', 42, 'ms');
 transaction.setMeasurement('metric.bar', 1337, 'nanoseconds');

dev-packages/browser-integration-tests/suites/public-api/startTransaction/circular_data/test.ts renamed to dev-packages/browser-integration-tests/suites/public-api/startSpan/circular_data/test.ts

@@ -43,8 +43,6 @@ export {
   makeMain,
   setCurrentClient,
   Scope,
-  // eslint-disable-next-line deprecation/deprecation
-  startTransaction,
   continueTrace,
   SDK_VERSION,
   setContext,

dev-packages/browser-integration-tests/suites/public-api/startTransaction/setMeasurement/subject.js renamed to dev-packages/browser-integration-tests/suites/public-api/startSpan/setMeasurement/subject.js

@@ -1,7 +1,6 @@
 import type {
   CaptureContext,
   CheckIn,
-  CustomSamplingContext,
   Event,
   EventHint,
   EventProcessor,
@@ -13,7 +12,6 @@ import type {
   Session,
   SessionContext,
   SeverityLevel,
-  TransactionContext,
   User,
 } from '@sentry/types';
 import { GLOBAL_OBJ, isThenable, logger, timestampInSeconds, uuid4 } from '@sentry/utils';
@@ -22,7 +20,6 @@ import { DEFAULT_ENVIRONMENT } from './constants';
 import { getClient, getCurrentScope, getIsolationScope } from './currentScopes';
 import { DEBUG_BUILD } from './debug-build';
 import type { Hub } from './hub';
-import { getCurrentHub } from './hub';
 import { closeSession, makeSession, updateSession } from './session';
 import type { ExclusiveEventHintOrCaptureContext } from './utils/prepareEvent';
 import { parseEventHintOrCaptureContext } from './utils/prepareEvent';
@@ -124,36 +121,6 @@ export function setUser(user: User | null): ReturnType<Hub['setUser']> {
   getIsolationScope().setUser(user);
 }
 
-/**
- * Starts a new `Transaction` and returns it. This is the entry point to manual tracing instrumentation.
- *
- * A tree structure can be built by adding child spans to the transaction, and child spans to other spans. To start a
- * new child span within the transaction or any span, call the respective `.startChild()` method.
- *
- * Every child span must be finished before the transaction is finished, otherwise the unfinished spans are discarded.
- *
- * The transaction must be finished with a call to its `.end()` method, at which point the transaction with all its
- * finished child spans will be sent to Sentry.
- *
- * NOTE: This function should only be used for *manual* instrumentation. Auto-instrumentation should call
- * `startTransaction` directly on the hub.
- *
- * @param context Properties of the new `Transaction`.
- * @param customSamplingContext Information given to the transaction sampling function (along with context-dependent
- * default values). See {@link Options.tracesSampler}.
- *
- * @returns The transaction which was just started
- *
- * @deprecated Use `startSpan()`, `startSpanManual()` or `startInactiveSpan()` instead.
- */
-export function startTransaction(
-  context: TransactionContext,
-  customSamplingContext?: CustomSamplingContext,
-): ReturnType<Hub['startTransaction']> {
-  // eslint-disable-next-line deprecation/deprecation
-  return getCurrentHub().startTransaction({ ...context }, customSamplingContext);
-}
-
 /**
  * Create a cron monitor check in and send it to Sentry.
  *