Changes

fix: increase tidb br integration test timeout duration (#3753)

The pass rate of the tidb BR integration test (pull_br_integration_test)
is relatively low, and a large number of builds fail due to timeout.
Analysis of Jenkins logs reveals the following:
1. The test is forcibly terminated by the SIGTERM signal during
execution (exit code 143).
2. The current timeout configuration is insufficient: total timeout is
60 minutes, and the timeout for a single test group is 45 minutes.
Adjust the timeout configuration as follows:
1. Total timeout: increased from 60 minutes to 90 minutes.
2. Test group timeout: increased from 45 minutes to 60 minutes.
 (commit: 0f857cb)