fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-FONTTOOLS-6133203
- https://snyk.io/vuln/SNYK-PYTHON-NUMPY-2321964
- https://snyk.io/vuln/SNYK-PYTHON-NUMPY-2321966
- https://snyk.io/vuln/SNYK-PYTHON-NUMPY-2321970

requirements.txt

@@ -1,5 +1,5 @@
 # Note that this file is not explicitly used by setup.py for EQcorrscan.
-numpy>=1.12
+numpy>=1.22.2
 matplotlib>=1.3.0
 scipy>=0.18,<1.9.0  # Pinned due to scipy/obspy hanning renaming
 bottleneck
@@ -14,3 +14,4 @@ pytest-mpl
 codecov
 pillow>=10.0.1 # not directly required, pinned by Snyk to avoid a vulnerability
 setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
+fonttools>=4.43.0 # not directly required, pinned by Snyk to avoid a vulnerability