Fix "referenced before assignment" warnings in padics #33186
Description
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2247:28: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2247:36: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2249:15: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2250:23: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2254:18: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:2254:46: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:759:28: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:759:33: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:761:42: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:763:42: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CA_element.pyx:763:67: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1187:28: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1187:33: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1189:24: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1191:24: local variable 'val' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1191:49: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1329:36: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1329:44: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1331:28: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1333:28: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_CR_element.pyx:1333:56: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1662:28: local variable 'valuation' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1662:39: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1663:11: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1666:19: local variable 'valuation' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1668:15: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1668:23: local variable 'valuation' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1671:23: local variable 'index' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/padic_ZZ_pX_FM_element.pyx:1671:31: local variable 'valuation' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/pow_computer_ext.pyx:1231:32: local variable 'minval' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/pow_computer_ext.pyx:1231:40: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/pow_computer_ext.pyx:1232:15: local variable 'mini' referenced before assignment
[sagelib-9.5.rc1] warning: sage/rings/padics/pow_computer_ext.pyx:1232:29: local variable 'minval' referenced before assignment
Component: build
Author: Michael Orlitzky
Branch/Commit: a584ff4
Reviewer: Frédéric Chapoton
Issue created by migration from https://trac.sagemath.org/ticket/33186