[DOCS] Update Debian APT repo command (#60679)

The current `tee` command appends a definition to
`/etc/apt/sources.list.d/elastic-{version}.list`.

This can lead to duplicate lines and significantly slow apt-get
operations.

This updates the command to overwrite rather than append.

docs/reference/setup/install/deb.asciidoc

@@ -49,7 +49,7 @@ ifeval::["{release-state}"=="released"]
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
-echo "deb https://artifacts.elastic.co/packages/{major-version}/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-{major-version}.list
+echo "deb https://artifacts.elastic.co/packages/{major-version}/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-{major-version}.list
 --------------------------------------------------
 
 endif::[]
@@ -58,7 +58,7 @@ ifeval::["{release-state}"=="prerelease"]
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
-echo "deb https://artifacts.elastic.co/packages/{major-version}-prerelease/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-{major-version}.list
+echo "deb https://artifacts.elastic.co/packages/{major-version}-prerelease/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-{major-version}.list
 --------------------------------------------------
 
 endif::[]
@@ -117,7 +117,7 @@ ifeval::["{release-state}"=="prerelease"]
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
-echo "deb https://artifacts.elastic.co/packages/oss-{major-version}-prerelease/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-{major-version}.list
+echo "deb https://artifacts.elastic.co/packages/oss-{major-version}-prerelease/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-{major-version}.list
 --------------------------------------------------
 
 endif::[]
@@ -126,7 +126,7 @@ ifeval::["{release-state}"!="prerelease"]
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
-echo "deb https://artifacts.elastic.co/packages/oss-{major-version}/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-{major-version}.list
+echo "deb https://artifacts.elastic.co/packages/oss-{major-version}/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-{major-version}.list
 --------------------------------------------------
 
 endif::[]