clarify version coverage and improve navigation for InfluxDB Docker README

Author: MeelahMe

.template-helpers/arches.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/opt/homebrew/bin/bash
 set -Eeuo pipefail
 
 repo="${1:-}"

.template-helpers/generate-dockerfile-links-partial.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/opt/homebrew/bin/bash
 set -Eeuo pipefail
 
 repo="${1:-}"

.template-helpers/variant.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/opt/homebrew/bin/bash
 set -eo pipefail
 
 repo="$1"