v1.15.3

## Fixes and improvements

General

* h264: fix DTS estimation of some HikVision cameras (https://github.com/bluenviron/mediamtx/issues/4617) (https://github.com/bluenviron/mediacommon/issues/252)

RTSP

* fix timeout when recording with FFmpeg and UDP (https://github.com/bluenviron/mediamtx/issues/5100) (https://github.com/bluenviron/gortsplib/issues/921)
* fix crash when calling PAUSE (https://github.com/bluenviron/gortsplib/issues/922) this happened when playing and protocol is UDP-multicast.
* use AVP profile when scheme is RTSPS and protocol is TCP (https://github.com/bluenviron/gortsplib/issues/916)

RTMP

* fix freeze when reading source (https://github.com/bluenviron/mediamtx/issues/5117) tracks were read without deadlines, freezing the server if they were not present. This patch also allows to close the server immediately during track reading.
* client: fix compatibility with SRS (https://github.com/bluenviron/mediamtx/issues/4630) (https://github.com/bluenviron/gortmplib/issues/9)

RPI Camera

* Added missing AnalogueGainMode (https://github.com/bluenviron/mediamtx-rpicamera/issues/71)

Dependencies

* code.cloudfoundry.org/bytefmt updated from v0.54.0 to v0.55.0
* github.com/bluenviron/gortmplib updated from v0.1.0 to v0.1.1
* github.com/bluenviron/gortsplib/v5 updated from v5.1.0 to v5.1.1
* github.com/bluenviron/mediacommon/v2 updated from v2.5.0 to v2.5.1
* github.com/pion/rtcp updated from v1.2.15 to v1.2.16
* github.com/pion/webrtc/v4 updated from v4.1.4 to v4.1.6
* github.com/pion/sctp updated from v1.8.39 to v1.8.40
* github.com/pion/transport/v3 updated from v3.0.7 to v3.0.8
* golang.org/x/mod updated from v0.28.0 to v0.29.0
* golang.org/x/tools updated from v0.37.0 to v0.38.0
* github.com/bluenviron/mediamtx-rpicamera updated from v2.5.0 to v2.5.1

## Security

Binaries are compiled from source through the [Release workflow](https://github.com/bluenviron/mediamtx/actions/workflows/release.yml) without human intervention, preventing any external interference.

You can verify that binaries have been produced by the workflow by using [GitHub Attestations](https://docs.github.com/en/actions/concepts/security/artifact-attestations):

```
ls mediamtx_* | xargs -L1 gh attestation verify --repo bluenviron/mediamtx
```

You can verify checksums of binaries by downloading `checksums.sha256` and running:

```
cat checksums.sha256 | grep "$(ls mediamtx_*)" | sha256sum --check
```