Bump numpy from 1.18.5 to 1.21.0 in /SIDGAN

Bumps [numpy](https://github.com/numpy/numpy) from 1.18.5 to 1.21.0.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.18.5...v1.21.0)

---
updated-dependencies:
- dependency-name: numpy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

SIDGAN/requirements.txt

@@ -1,7 +1,7 @@
 Keras==2.3.1
 tensorflow_gpu==2.5.1
 scipy==1.2.0
-numpy==1.18.5
+numpy==1.21.0
 opencv_python==4.4.0.42
 Pillow==8.3.2